Learning PostgreSQL 11 - Third Edition

Assignment statements

An assignment statement is used to assign a value to a variable. Constants are assigned values at the time of declaration. The variable can be assigned an atomic value or a complex value, such as a record. Also, it can be assigned a literal value or a result of query execution.

The assignment := and =, operators are used to assign an expression to a variable, as follows:

variable { := | = } expression;

For the variable names, you should choose names that do not conflict with the column names. This is important when writing parameterized SQL statements. The = operator is used in SQL for equality comparisons; it is preferable to use the := operator, in order to reduce confusion.

In certain contexts, the operators = and ...