Class GF_Query_Column

The Gravity Forms Query Column class.

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

Methods summary
`public`	# `__construct( string $field_id, integer\|array $source = 0, string\|boolean $alias = false )` Represents a column. Represents a column. Parameters `$field_id` The field ID (meta key or column name). `$source` The source this field is referencing. `$alias` An alias override. Default: false.
`public string`	# `sql( $query )` Get some SQL for this column. Get some SQL for this column. Parameters `$query` The query. Returns string The SQL.
`public boolean`	# `is_entry_column( )` Whether this field is an entry column. Whether this field is an entry column. Returns boolean An entry column or not.
`public boolean`	# `is_nullable_entry_column( )` Whether this field is a nullable entry column. Whether this field is a nullable entry column. Returns boolean An entry column or not. Since 2.3.1.10
`public boolean`	# `is_meta_column( )` Whether this field is a meta column. Whether this field is a meta column. Returns boolean A meta column or not.
`public`	# `__get( $key )` Proxy read-only values. Proxy read-only values.

Constants summary
`string`	`META` Const Identifier for searching across any meta field.	# `'{{ANY META FIELD}}'`