How to declare and use a variable in postgresql?

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by rollin , in category: MySQL , 25 days ago

How to declare and use a variable in postgresql?

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1 answer

Member

by deron , 24 days ago

@rollin 

In PostgreSQL, you can declare and use a variable within a PL/pgSQL block. Here's an example:

  1. To declare a variable, use the DECLARE keyword followed by the variable name and data type:
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DO $$
DECLARE
    my_variable INTEGER;
BEGIN
    -- Your SQL statements here
END $$;


  1. To assign a value to the variable, use the := operator:
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DO $$
DECLARE
    my_variable INTEGER;
BEGIN
    my_variable := 10;
END $$;


  1. To use the variable in your SQL statements, simply reference it by name:
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DO $$
DECLARE
    my_variable INTEGER;
BEGIN
    my_variable := 10;

    SELECT * FROM some_table WHERE column = my_variable;
END $$;


Remember that variables declared in a PL/pgSQL block are only accessible within that block. To use a variable in a different block, you can pass it as a parameter or store it in a table.