Boolean (Logical) Values

2017-11-03 09:05:05

PostgreSQL supports a single Boolean (or logical) data type: BOOLEAN (BOOLEAN can be abbreviated as BOOL).

Size and Valid Values

A BOOLEAN can hold the values TRUE, FALSE, or NULL, and consumes a single byte of storage.

Syntax for Literal Values

Table 2.16 shows the alternate spellings for BOOLEAN literals.

Table 2.16. `BOOLEAN` Literal Syntax
Common Name	Synonyms
`trUE`	`true`, `'t'`, `'y'`, `'yes'`, `1`
`FALSE`	`false, 'f', 'n', 'no', 0`

Supported Operators

The only operators supported for the BOOLEAN data type are the logical operators shown in Table 2.17:

Table 2.17. Logical Operators for `BOOLEAN`
Data Types	Valid Operators (q)
`BOOLEAN` q `BOOLEAN`	`AND OR NOT`

I covered the AND, OR, and NOT operators in Chapter 1. For a complete definition of these operators, see Tables 1.3, 1.4, and 1.5.

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