PostgreSQL Reference Manual - Volume 1 - SQL Language Reference by The PostgreSQL Global Development Group Paperback (6"x9"), 716 pages ISBN 0954612027 RRP £32.00 ($49.95) Sales of this book support the PostgreSQL project! Get a printed copy>>>

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8 Type Conversion

SQL statements can, intentionally or not, require mixing of different data types in the same expression. PostgreSQL has extensive facilities for evaluating mixed-type expressions.

In many cases a user will not need to understand the details of the type conversion mechanism. However, the implicit conversions done by PostgreSQL can affect the results of a query. When necessary, these results can be tailored by using explicit type conversion.

This chapter introduces the PostgreSQL type conversion mechanisms and conventions. Refer to the relevant sections in section 6 Data Types and section 7 Functions and Operators for more information on specific data types and allowed functions and operators.