Plpgsql Declare Table Variable

However, there are huge drawbacks of using table variables when you process a lot of rows. So for that i need two variable where i can store the filter values and remainning calculation will be done according to the years stored in the variables. The TYPE OF modifier allows using only the domain's datatype and not its NOT NULL setting, CHECK constraint and/or default value. So I had to start up my virtual machine and try it out, because this would be a awesome new feature. In PostgreSQL, every table name serves as type name for the row type (a. The first letter should be used to specify the declared level of the variable. ) PL/pgSQL has four forms of the OPEN statement, two of which use unbound cursor variables and the other two use bound cursor variables. The register keyword is used to declare register variables. First we create a temporary table named tmp with a single field named content. This is especially an issue when referring to a table variable’s column in correlated subqueries with column name ambiguity. In this chapter, we will discuss the advanced use of variables and arguments. ) PL/pgSQL has three forms of the OPEN statement, two of which use unbound cursor variables while the third uses a bound cursor variable. Apart from this, there are few other differences between a Table Variable and a Temporary Table. Here is a simple test case (original is more complex with a multi-table query in the for qres in select. email" to make that unambiguous. The primary key will represent a clustered index, while the unique constraint a non clustered index. It allows to check source code by explicit call plpgsql_check_function. SET; SET STATEMENT; DECLARE Variable. PostgreSQL Functions. Many believe that table variables exist only in memory, but that is simply not true. Hi, Is there a way in sas to declare a variable once and use it in multiple procedures? The thing is I am using a table named "blue_cars_table" in multiple procedures and instead of writing blue_cars_table I would like to write a variable, so if a user want to change the code quickly, he just have to change the table name once. But either option will work. Nested tables. integers, chars, floats, boolean etc) or references to Java objects. You declare and use variables in whatever program you write > that runs SQLite statements. DECLARE @TestId1 INT DECLARE @TestId2 INT SELECT IType. Name AS IType ,COUNT (*) AS CNT FROM dbo. But, it does not compile and I can't work out why. This is called variable. Execute a statement for each row of a table. Opening Cursors. If a name used in a SQL command could be either a column name of a table or a reference to a variable of the function, PL/SQL treats it as a column name. A table variable can have multiple columns. A previously declared variable into which a select_item value is fetched. PLpgSQL is simple (but relatively powerful) specialized language. Is Table Variable Memory Only Object? Here is the article where I have explained previously that table variable are created in a temporary database just like temporary table. In VHDL-93, shared variables may be declared within an architecture, block, generate statement, or package: shared variable variable_name : type; Shared variables may be accessed by more than one process. actual rows in plan execution has a lot of impact in query performance, and the source of these skews can be quite diverse, from outdated statistics, to incorrect sampling, or the inability of the query processor to know the value of certain variables at compile time, just. This can change throughout a SQL script, thus providing great flexibility. This is especially an issue when referring to a table variable’s column in correlated subqueries with column name ambiguity. For supported data types, see Data Types. This parameter accepts a variable with one condition that all arguments have the same data type. Additionally, please do not use keyword GO between DECLARE and SELECT statement when you are using table variable as it will reset the declaration of the table variable. Importing with a variable filename is a requirement. composite type) automatically - not a table type, there are no "table types" or "table variables" in Postgres (but there are typed tables). The PL/pgSQL function is a little more complicated, but let's go through it. These keywords divide the block into a declarative part, an executable part, and an exception-handling part. Indexes on Table Variables It is a common misunderstanding when comparing temporary tables and table variables that one difference is that table variables cannot have indexes. Just like any local variable we create with a DECLARE statement, a table variable is also scoped to the stored procedure, batch, or user-defined function. Before a cursor can be used to retrieve rows, it must be opened. If you're using temporary tables and don't need transactions on those tables and want better performance I'd strongly consider using table variables instead. Transactions that involve table variables last only for the duration of an update on the table variable. The register keyword is used to declare register variables. plpgsql_check is next generation of plpgsql_lint. A variable holds a value that can be changed through the block or function. Operator TABLE informs Oracle that the value is a collection, not a scalar value. In this syntax, you specify the name of the table variable between the DECLARE and TABLE keywords. Table Variables. Because local variables are in scope only during stored program execution, references to them are not permitted in prepared statements created within a stored program. This corresponds to PL/pgSQL 's plpgsql. Nice to see someone else confirm my experience - e. They are dropped when the connection is closed. Name AS IType ,COUNT (*) AS CNT FROM dbo. Variable Scope. Let’s first focus on why dynamic SQL or SSIS variables are required. However, unlike SQL temp tables the table variable is only accessible within the current batch. Thanks in Advance. The NEW variable is a special variable of type RECORD holding the new row to be inserted or updated. My Tablename name needs to be variable and I will build it on the fly. First, let’s look at an example of the problem. PL/pgSQL variables can be any Amazon Redshift supported data type, plus RECORD and refcursor. Consider the following example:. Although Pascal is case insensitive, reserved words and modifiers are customarily written in lower case. You declare and use variables in whatever program you write > that runs SQLite statements. You may also assign a value to the variable at the time of declaration. Indexes on Table Variables It is a common misunderstanding when comparing temporary tables and table variables that one difference is that table variables cannot have indexes. SQL TABLE Variable. fails on NULL in record variables Hi all, I'm currently coding some functions in plpgsql for generating reports out of records in a table. data: cust_tab like sorted table of kna1 with unique key kunnr initial size 5 with header line. Free Oracle Magazine Subscriptions and Oracle White Papers: Oracle Bind Variables: Version 11. Usage of these variables is very simple – using functions. Learn vocabulary, terms, and more with flashcards, games, and other study tools. It is not possible to use ROW TYPE OF variables in a LIMIT clause. Hello, In pl/pgsql (postgresql 8. >My question would be how to tell VFP a variable is the field name in database table or is a variable I declared in "local"? Let me answer that one more direct: As you can access a field of a table by it's mere name, names can be field or variable names. To assign a value, use the equal sign: var age; age = 55; The first line declares a variable called age. The syntax is as follows: "DECLARE @Temporary TABLE (an INT). But, it does not compile and I can't work out why. You can use table-valued parameters to send multiple rows of data to a Transact-SQL statement or a routine, such as a stored procedure or function, without creating a temporary table or many parameters. Lines 5-11: This BEGIN/END block of code, holds the original query we started with. Variables declared with ROW TYPE OF will have the same features as implicit ROW variables. Lines 5–11: This BEGIN/END block of code, holds the original query we started with. (Since every table has an associated composite type of the same name, it actually does not matter in PostgreSQL whether you write %ROWTYPE or not. You can specify location as a variable name, or a numeric or logical index. Be One with the Optimizer TG. Here I am trying to discuss about the Table variable with dynamic SQL constructs and how to use the table variable in the dynamic SQL. Fortunately, this is an easy limitation to circumvent. If the referenced item changes, your declaration is automatically updated. Like Local Variables, Table variable scope is limited to User Defined Functions or Stored procedures. Microsoft introduced table variables with SQL Server 2000 as an alternative to using temporary tables. The primary key will represent a clustered index, while the unique constraint a non clustered index. A variable declaration always specifies the name and data type of the variable. You can define variables with both scalar values and tables. must declare the variable @tablename, which has already been declared. The first letter should be used to specify the declared level of the variable. Or Table value function. Microsoft's monopoly, used in SQL Server. This statement detect all columns in SQL query and implicitly creates correspondent variables with correct type. This can change throughout a SQL script, thus providing great flexibility. We saw two reasons for using table variables rather than temp tables. A PostgreSQL function or a stored procedure is a set of SQL and procedural statements (declarations, assignments, loops, flow-of-control etc. This video teaches you how to declare table. It is not persistent and cannot be shared with other application processes. 0), or as the table column (which is compatible with some other systems such as Oracle). In this article, you will learn the. You certainly know that implementing dynamic triggers in PLpgSQL is impossible. A local variable should be declared as any system or user defined data type. A variable declared inside a block is accessible to that block alone. Microsoft's monopoly, used in SQL Server. DECLARE @tbl TABLE (RowID INT IDENTITY, descr varchar(10) ) insert into @tbl. Let's step over some more steps. There are advantages to each depending on the circumstances. It is a variable where we temporary store records and results. -- check_all: -- * run all of the checks and return a table of results drop type if exists TestingResult cascade; create type TestingResult as (test text, result text); create or replace function check_all() returns setof TestingResult as $$ declare i int; testQ text; result text; This preview has intentionally blurred sections. This video teaches you how to declare table. A variable declaration always specifies the name and data type of the variable. I am rying to run a TSQL SELECT Count(*) that has a @Tablename variable in it. ) that stored on the database server and can be invoked using the SQL interface. They may perform better especially if the tables are small. In most cases SET. There are also reasons for using temp tables instead of table variables. Step:1, Creating User defined Table Type Create Type IntergerType As Table(ID Int) Step:2, Declaring Table variable using the User defined Table valued Type just we created and Inserting Data. Just a guess… Gail has shown table variables always get written to pages in tempdb, so the question of if pages holding table variable data go to disk could be the same as for any page in tempdb getting written to disk. Temporary tables. In SQL Server a variable is typical known as a local variable, due the scope of the variable. Hence, they are out of scope of the transaction mechanism, as is clearly visible from this example:. It's really not as complicated as it may sound, but there are a few trapdoors to avoid. Declare Temporary Table variable / iterate over a cursor USE [SMS]. function-body contains the executable part. PL/pgSQL allows you to create anonymous cursors using REFCURSOR variables. Pay attention what variable names used in plpgsql functions to prevent errors, e. That is, the variable can be used anywhere else in the script, but it will not be visible to other scripts called using EXECUTE, nor to the parent script if this script was itself called with EXECUTE. In this example, RedProducts and LastYear are tables, not scalar values. Basically the scope of the local variables is within the batch in which it is declared. The table variable contains one column which must be a scalar or record datatype plus a primary key of type BINARY_INTEGER. Variables can use any valid Amazon Redshift data type. This is especially an issue when referring to a table variable’s column in correlated subqueries with column name ambiguity. The below point give the different first letters and their declarative level 'P' – Variable is declared at the parameter level 'L' – Variable is declared at the local block. Before evaluation, occurrences of PL/pgSQL variable identifiers are replaced by parameters, and the actual values from the variables are passed to the executor in the parameter array. Unlike sql functions which currently require you to refer to variables by their ordinal position $1, $2, $3 etc. Be One with the Optimizer TG. Iterating over collection variables [PL/SQL] These are cook book recipes that show, for each of the three collection types , how to iterate over their elements. Because local variables are in scope only during stored program execution, references to them are not permitted in prepared statements created within a stored program. Think of a variable as a box that acts as a place holder for whatever value you want to put in it. It has attributes for each column of that table, which can then be assigned to. (Since every table has an associated composite type of the same name, it actually does not matter in PostgreSQL whether you write %ROWTYPE or not. Whenever you declare a record type variable oracle engine will declare a composite data structure with fields corresponding to each column of the specified table. Home » Answers » Does Jasper reports support temp tables and declare variables? Does Jasper reports support temp tables and declare variables? Posted on June 19, 2015 at 8:30am. If a variable is not initialized to a default value when it is declared, its value will default to the SQL NULL type. The functionality is the same as a temporary table. You can specify location as a variable name, or a numeric or logical index. However, unlike SQL temp tables the table variable is only accessible within the current batch. I have in issue in update @temp table column from another table column value. Declare x as a global variable at the command line, and display its value. Both fulfill the task, but in some scenarios unexpected results may be produced. This works fine: SET NOCOUNT ON. I have tried creating the table type and insertion as below:. There are also reasons for using temp tables instead of table variables. The variable's name represents what information the variable contains. The table name and field must be called every time instead of a custom variable. Thanks Karthick! There must be another way to load the data from another table. Temporary tables. Toutes les variables utilisées dans un bloc doivent être déclarées dans la section déclaration du bloc, sauf la variable de boucle d'une boucle FOR (déclarée automatiquement comme variable de type integer). Another point that might not be obvious is that variables are part of an expression. Variable declarations or assignment of values may create a container on the fly. These variables are filled by implicit FETCH statement every statement cycle. Transactions that involve table variables last only for the duration of an update on the table variable. In PL/SQL, records are used to group data. Declare, assign, and use variables in SQL-Server A variable is a user-friendly name given to an area of memory that stores a value. If a variable is not initialized to a default value when it is declared, its value will default to the SQL NULL type. This is a very popular question and let us see the answer to this question in this blog post. CREATE FUNCTION check_shipment_addition RETURNS opaque AS ' DECLARE -- Declare a variable to hold the customer ID. I need some variables in the first function to be available in the nested function. I've long used this Stack Overflow query from Sam Saffron to illustrate terrible cardinality estimation: [crayon-5db72952624d3672139673/] It puts a bunch of data into a table variable, and then queries that same table variable. Both constants and variables provide a way to reserve memory locations for the storage of values of various types (such as numbers, characters and strings). email" to refer to the variable unambiguously. Declare a variable named cartHTML that will contain the HTML code for the contents of the shopping cart, which will be displayed as a table. Only the type itself is used; in the case of string types, this includes the character set and the collation. When you declare a CURSOR variable, you are really creating a PostgreSQL cursor whose name is the same as the name of the variable. If a table variable is declared in a stored procedure, it is local to that stored procedure and cannot be referenced in a nested procedure There are also no statistics-based recompiles for table variables and you can't ALTER one, so routines that use them tend to incur fewer recompiles than those that use temporary tables. SQL Server (2008): Passing Table Parameter to Stored Procedure - posted in Database Tutorials: Prior SQL Server 2008, in SQL Server 200 to be exact (I never have serious project with SQL Server 2005), I always wondering why we could not pass a table variable to a stored procedure. [In the message "[sqlite] Re: how do i declare and use variables in sqlite?" on Aug 2, 18:22, "Igor Tandetnik" writes:] > Chase <[hidden email]> wrote: > > how do i declare and use variables in sqlite? > > You don't. Ironically, the name of the Table Variable is fixed, but because it's a "variable", it can't be used to import. My trial: whose output is the same as from Table[h[i,j],{i,3},{j,3}]. The problem is that PostgreSQL don´t support variables, except PL/pgSQL. The table data type lets you define a variable that holds a complete table. Assigning a value to a variable means storing a value to a variable. po to fr_fr # french message translation file for plpgsql # # Use these quotes: « %s » # Guillaume Lelarge ,. num = 4; Given two double variables , bestValue and secondBestValue , write some code that swaps their values. Hello, i have a function which has a nested function in it. The declared temporary table resides in the work file database and its description does not appear in the system catalog. As I have already mentioned that Table is a data type in SQL Server that is why we use. Rate this:. The NEW variable is a special variable of type RECORD holding the new row to be inserted or updated. The following example shows an invalid use of the AS keyword with a table variable: DECLARE @mytable AS table ( col1 int NOT NULL ) You must remove the AS keyword to make this code valid: DECLARE @mytable table ( col1 int NOT NULL ) T-SQL supports only local variables. To declare a variable with the same datatype as users you do: user_id users. All variables and constants must be declared before they are referenced. A STRING type variable is different from a CHAR(n) type variable in the following aspects: · When string data is assigned to a CHAR(n) variable, the resultant string is always n characters long. The optional exception-handling part is used to handle run time errors. When you use a table variable in a batch or procedure, the query is compiled and optimized for the initial empty state of table variable. Table variable is a very useful programming construct, like that of any other. EXEC SQL DECLARE TABLE statement which gives the layout of the table/view in terms of DB2 datatypes. SAP ABAP Declare a variable which is used in anoth SAP ABAP Declare a type which is used in another t SAP ABAP Declare a constant which type is the same SAP ABAP Declare all types and constants from type SAP ABAP Declare a work area of 5 constant compone SAP ABAP Declare a work area of constants. In a PL/pgSQL FOR loop an integer variable is stated first, to track the iteration of the loop, then the integer range is given,. In PostgreSQL, every table name serves as type name for the row type (a. The DECLARE GLOBAL TEMPORARY TABLE statement defines a declared temporary table for the current application process. We declare variables of these types similarly to specifying columns in tables. It's really not as complicated as it may sound, but there are a few trapdoors to avoid. A variable declaration always specifies the name and data type of the variable. It is a variable where we temporary store records and results. After you have declared a string, only its type is defined. (sorry my previous email was truncated) hi, Here is what I want to do : I want to check each row of a table against some conditions (this check needs. This sounds simple, but I can't find how to do the insert in a simple generic fashion: although SELECT has a form that puts the result in a record variable, INSERT doesn't seem to. So you would have to write the whole set of statements to create and operate on the table variable, and perform it with a single call to EXEC or sp_executeSQL. When you declare a CURSOR variable, you are really creating a PostgreSQL cursor whose name is the same as the name of the variable. DECLARE command is used to DECLARE variable which acts as a placeholder for the memory location. Anything not recognized as one of these statement types is presumed to be an SQL query, and is sent to the main database engine to execute (after substitution for any PL/pgSQL variables used in the statement). And you can qualify a table column with the table name, like "pass. must declare the variable @tablename, which has already been declared. Table variables may not have any dependent objects such as triggers or foreign keys. PL/pgSQL Declaration : All variables must be declared in the declarations section of the block. A variable is always associated with a particular data type. The AS keyword is used for creating a standalone function. The user-defined variables are not case-sensitive. Gomez When thinking about the main purpose of Visual Basic for Applications, I usually go to the following quote by one of my favorite Excel authors, John Walkenbach. so the syntax of the Table Variable is as follows:. Think of it like a table with a single row of data. PL/pgSQL variables will be substituted into the rest of the query, and the plan is cached, just as described above for commands that do not return rows. When you declare an internal table, the line type, access type, and key are defined. What is a variable in PostgreSQL? In PostgreSQL, a variable allows a programmer to store data temporarily during the execution of code. I need some variables in the first function to be available in the nested function. In one of my company's excel sheet, i saw this: Code: VLOOKUP(H4177,SOME_VARIABLE_NAME,3,FALSE) How can i find where this `SOME_VARIABLE_NAME` table i Declare variable for table_array in VLOOKUP? Help. To create a new Table variable, right-click within the page and choose New Item from the context menu. Just a guess… Gail has shown table variables always get written to pages in tempdb, so the question of if pages holding table variable data go to disk could be the same as for any page in tempdb getting written to disk. itemno = p_itemno; END; $$ LANGUAGE plpgsql;. Explicit Cursors. SQL is a language where one task can be solved multiple ways with different efficiency. Local Variables All the variables we have used thus far have been local variables. They are also not. To set up a cursor, first you declare a cursor variable. Both stored procedures and user-defined functions are created with CREATE FUNCTION statement in PostgreSQL. The method of transfer of the final value is the main different between procedure and function. Before using any variable in batch or procedure, you need to declare the variable. One way to create a cursor variable is just to declare it as a variable of type refcursor. Notice that we are using the NEW variable to get the customer_id, name and balance of the new customer being inserted. You can use table-valued parameters to send multiple rows of data to a Transact-SQL statement or a routine, such as a stored procedure or function, without creating a temporary table or many parameters. Table3 ON ***** LEFT JOIN dbo. Is there a way to do that? There has to be otherwise these "table variables" are pretty useless. It is great language for this purpose (and can be bad if it is used differently - for high cycles numeric calculation for example). plpgsql : adding record variable to table. Variable hold single data value. This can change throughout a SQL script, thus providing great flexibility. When you try and access the variable, you will either get another exception or worse, use an old or invalid variable value. The structure of a FOR loop in PL/pgSQL is similar to FOR loops in other procedural languages, such as C. To reference the table variable inside a SELECT statement, SQL Server requires that you give the table variable an alias, otherwise you'll get an error: Must declare the scalar variable "@TableVariableName". I would prefer to insert the values into a table variable and join to that table rather than using dynamic SQL. PL/pgSQL is specific because of its support only to the proposals of function, not procedures. Many believe that table variables exist only in memory, but that is simply not true. Table variables are created like any other variable, using the DECLARE statement. So you can just declare a variable of that type in PL/pgSQL. I have in issue in update @temp table column from another table column value. If the source string is longer, it is truncated to n characters. file - the quoted file name that the function was called with; tmp - the quoted unique name for a temporary table; Once we have our variables all setup, we EXECUTE some SQL to read the file contents. However, nothing prevents you from creating table variables based on memory optimized table types and use those for other purposes, including passing them as TVPs to. Variables have script scope. These are placeholders that store the values that can change through the PL/SQL Block. Like Local Variables, Table variable scope is limited to User Defined Functions or Stored procedures. Variables are created during program execution and destroyed after program execution. SQL Server Programming Part 9 - Table Variables Table Variables provide an alternative to Temporary Tables when working with temporary sets of data. (sorry my previous email was truncated) hi, Here is what I want to do : I want to check each row of a table against some conditions (this check needs. In queries that modify table variables, parallel plans will not be used. The clear advantage to me is the ability to pass a table variable as a parameter, but the use case for those seems limited, and the overhead (creating a table variable type) is too much. If a name used in a SQL command could be either a column name of a table or a reference to a variable of the function, PL/SQL treats it as a column name. -- check_all: -- * run all of the checks and return a table of results drop type if exists TestingResult cascade; create type TestingResult as (test text, result text); create or replace function check_all() returns setof TestingResult as $$ declare i int; testQ text; result text; This preview has intentionally blurred sections. By default, a cursor gets the next row if you don’t specify the direction explicitly. Table variables can be used instead of temporary tables. (This is the equivalent action to the SQL command DECLARE CURSOR. Declare TABLE TYPE variables in a PL/SQL declare block. A student asked how you print output from PL/pgSQL blocks. The Variable can be declared as TEMP - then the catalog changes and the accessibility of variable is limited by session or by transaction. All variables that you will be using within a code block must be declared under the DECLARE keyword. I'm trying to declare and populate a table variable within. In this article, you will learn about the main differences between Temp Table, Table variable and CTE. Opening Cursors. Variables can be created and modified in a variety of ways. Row-type variables can hold a whole row of a query result, providing that the query’s column set matches the declared type of the variable. Apart from this, there are few other differences between a Table Variable and a Temporary Table. Then we move into the BEGIN block and set a couple of variables. Create delete queries that delete all rows from production table where the timestamp is <= the variable. The specific place that variables are declared influences how various functions in a program will see the variable. How to Declare and Initialize Variables in T-SQL - Part 2 and what are the differences between scalar and table variables? Is a variable declared in one session available for access in other. Variable names can start with or without a special character called a sigil, followed optionally by a second special character named twigil and then an identifier. Then we move into the BEGIN block and set a couple of variables. The syntax is as follows: "DECLARE @Temporary TABLE (an INT). Declare, assign, and use variables in SQL-Server A variable is a user-friendly name given to an area of memory that stores a value. When you try and access the variable, you will either get another exception or worse, use an old or invalid variable value. For a large table, using a table variable is very often a bad practice… Statistics First, they do not have any statistics (statistics are used by the query optimizer to produce the most efficient query plan based on data distribution). Thanks in Advance. As mentioned earlier, Redshift allows you to create a stored procedures using postgre plpgsql language. COUNT The number of elements (rows) in the plsql table FIRST First and Last index no. I'm new to plpgsql. So you can just declare a variable of that type in PL/pgSQL. Many believe that table variables exist only in memory, but that is simply not true. Example - Declare a variable. I have a table type with one column and I want to create one with two columns. Think of a variable as a box that acts as a place holder for whatever value you want to put in it. On the other hand, temporary tables are only available to the current connection to the database for the current user. Only the type itself is used; in the case of string types, this includes the character set and the collation. Microsoft's monopoly, used in SQL Server. The table variable contains one column which must be a scalar or record datatype plus a primary key of type BINARY_INTEGER. The same syntax for inline index create listed above works just fine for me on temporary tables in my CTP of SQL Server 2014. You can use Set statement to assign Workbook Object to a variable. The DECLARE LOCAL TEMPORARY TABLE statement declares a temporary table. The query which works fine with temporary table does not work with table variables. In such cases you can specify that PL/pgSQL should resolve ambiguous references as the variable (which is compatible with PL/pgSQL 's behavior before PostgreSQL 9. Notice that we are using the NEW variable to get the customer_id, name and balance of the new customer being inserted. The NEW variable is a special variable of type RECORD holding the new row to be inserted or updated. The register keyword is used to declare register variables. For supported data types, see Data Types. Also creates the DECLARE table. You can open a cursor, and repeatedly fetch a tuple then move the cursor, until all tuples have been retrieved. DECLARE @TestId1 INT DECLARE @TestId2 INT SELECT IType. Variables are created during program execution and destroyed after program execution. My Tablename name needs to be variable and I will build it on the fly. Same happens when you declare some variable as global in function, it receives same address as global variable outside of function. I need some variables in the first function to be available in the nested function. Functions modifying table contents must be declared volatile STABLE Returns same result for same arguments within single query Example: now() Consider con guration settings that a ect output IMMUTABLE Always returns the same result for the same arguments Example: lower(’ABC’) Una ected by con guration settings Not dependent on table contents. DATA: firstname(10) TYPE c, index TYPE i, student_id(5) TYPE n. Today I needed to write a stored mysql procedure which could take a parameter and create a new table with the name same as the value of this parameter. Think of a variable as a box that acts as a place holder for whatever value you want to put in it. PL/SQL Variables. All access to cursors in PL/pgSQL goes through cursor variables, which are always of the special data type refcursor. If a variable is not initialized then it defaults to NULL value. If you use a long date format in your variable initialisation, you don't always need to use TO_DATE, as shown below: SQL>VAR DATE_VAL VARCHAR(30); SQL>EXEC :DATE_VAL := '31 MARCH 2018' In some cases, you can use the date without needing to use TO_DATE:. Toutes les variables utilisées dans un bloc doivent être déclarées dans la section déclaration du bloc, sauf la variable de boucle d'une boucle FOR (déclarée automatiquement comme variable de type integer). The clear advantage to me is the ability to pass a table variable as a parameter, but the use case for those seems limited, and the overhead (creating a table variable type) is too much. A variable declared with a record type can hold one row of data consisting of a number of column values. In the previous example, you created one cursor (not just a cursor variable) named next_rental and a cursor named next_tape. The above PL/pgSQL shows an alias for the function argument have been declared, which should be the id of the employee and a variable found_employee that uses the structure of the employees table have also been declared. So you can just declare a variable of that type in PL/pgSQL.