Class GF_Query_Condition

The Gravity Forms Query Condition class.

Located at query/class-gf-query-condition.php

Methods summary
`public GF_Query_Condition`	# `__construct( GF_Query_Column\|GF_Query_Call\|GF_Query_Literal\|null $left = null, string\|null $operator = null, GF_Query_Column\|GF_Query_Call\|GF_Query_Literal\|GF_Query_Series\|null $right = null )` A condition. A condition. Parameters `$left` The left-hand expression. `$operator` The operator. `$right` The right-hand expression. Returns `GF_Query_Condition` $this This condition.
`public static GF_Query_Condition`	# `_and( )` Tie several conditions together with an AND relationship. Tie several conditions together with an AND relationship. Accepts any number of GF_Query_Condition objects. Returns `GF_Query_Condition` The condition.
`public static GF_Query_Condition`	# `_or( )` Tie several conditions together with an OR relationship. Tie several conditions together with an OR relationship. Accepts any number of GF_Query_Condition objects. Returns `GF_Query_Condition` The condition.
`public string`	# `sql( GF_Query $query )` Compile the expressions into a SQL string. Compile the expressions into a SQL string. Parameters `$query` The query. Returns string The SQL string.
`public static boolean`	# `is_valid_expression_type( mixed $expression )` Checks whether the expression is of a valid type. Checks whether the expression is of a valid type. Parameters `$expression` The expression to check. Returns boolean Valid or not.
`public array`	# `get_columns( )` Retrieve all the columns present in the left, right clauses. Retrieve all the columns present in the left, right clauses. Returns array The columns.
`public`	# `__get( $key )` Proxy read-only values. Proxy read-only values.

Constants summary
`string`	`_AND` Const string The AND operator.	# `'AND'`
`string`	`_OR` Const string The AND operator.	# `'OR'`
`string`	`LT` Const string The less than operator.	# `'<'`
`string`	`LTE` Const string The less than or equal to operator.	# `'<='`
`string`	`GT` Const string The greater than operator.	# `'>'`
`string`	`GTE` Const string The greater than or equal to operator.	# `'>='`
`string`	`EQ` Const string The equal to operator.	# `'='`
`string`	`NEQ` Const string The not equal to operator.	# `'!='`
`string`	`IN` Const string The IN operator.	# `'IN'`
`string`	`NIN` Const string The NOT IN operator.	# `'NOT IN'`
`string`	`LIKE` Const string The LIKE operator.	# `'LIKE'`
`string`	`NLIKE` Const string The NOT LIKE operator.	# `'NOT LIKE'`
`string`	`BETWEEN` Const string The BETWEEN operator.	# `'BETWEEN'`
`string`	`NBETWEEN` Const string The NOT BETWEEN operator.	# `'NOT BETWEEN'`
`string`	`CONTAINS` Const string The inverse IN operator.	# `'CONTAINS'`
`string`	`NCONTAINS` Const string The inverse NIN operator.	# `'NCONTAINS'`