Update wiki Expressions page.
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@ -14,216 +14,148 @@ Jet sql builder supports following expression types:
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_This list might be extended with feature Jet releases._
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### Literal type
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For every expression type there is a method to create one literal type expressions.
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For every expression type there is a method to create one expression literal type .
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Literal type examples:
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```
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Bool(true)
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Integer(11)
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Float(23.44)
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String("John Doe")
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Date(2010, 12, 3)
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Time(23, 6, 6, 1)
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Timez(23, 6, 6, 222, +200)
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Timestamp(2010, 10, 21, 15, 30, 12, 333)
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Timestampz(2010, 10, 21, 15, 30, 12, 444, 0)
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jet.Bool(true)
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jet.Integer(11)
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jet.Float(23.44)
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jet.String("John Doe")
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jet.Date(2010, 12, 3)
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jet.Time(23, 6, 6, 1)
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jet.Timez(23, 6, 6, 222, +200)
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jet.Timestamp(2010, 10, 21, 15, 30, 12, 333)
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jet.Timestampz(2010, 10, 21, 15, 30, 12, 444, 0)
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NULL
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STAR (alias for *)
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jet.NULL
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jet.STAR (alias for *)
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```
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### Column types
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Every sql builder table column belongs to one expression type. There are following column types:
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```
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ColumnBool
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ColumnInteger
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ColumnFloat
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ColumnString
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ColumnDate
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ColumnTime
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ColumnTimez
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ColumnTimestamp
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ColumnTimestampz
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jet.ColumnBool
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jet.ColumnInteger
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jet.ColumnFloat
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jet.ColumnString
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jet.ColumnDate
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jet.ColumnTime
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jet.ColumnTimez
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jet.ColumnTimestamp
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jet.ColumnTimestampz
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```
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Columns and literals can form arbitrary expressions but have to follow valid SQL expression syntax.
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For instance valid expressions are:
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```
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Bool(true).AND(Bool(false)).IS_FALSE()
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(Film.Length.GT(Int(100)).AND(Film.Length.LT(Int(200))).IS_TRUE() // table 'film', integer column 'length'
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jet.Bool(true).AND(jet.Bool(false)).IS_FALSE()
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(table.Film.Length.GT(jet.Int(100)).AND(table.Film.Length.LT(jet.Int(200))).IS_TRUE()
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```
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Some of the invalid expressions. These expressions will cause go build to break.
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```
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Bool(true).AND(Int(11)) // can't compare bool and
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Int(11).ADD(Float(22.2)) // can't add integer and floats, but
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// using cast it is possible: Int(11).TO_FLOAT().ADD(Float(22.2))
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```
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jet.Bool(true).ADD(jet.Int(11)) // can't add bool and integer
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jet.Int(11).LIKE(jet.Float(22.2)) // integer expressions doesn't have LIKE method
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```
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## Common expression operators
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```go
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type Expression interface {
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clause
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projection
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groupByClause
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OrderByClause
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// Test expression whether it is a NULL value.
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IS_NULL() BoolExpression
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// Test expression whether it is a non-NULL value.
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IS_NOT_NULL() BoolExpression
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// Check if this expressions matches any in expressions list
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IN(expressions ...Expression) BoolExpression
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// Check if this expressions is different of all expressions in expressions list
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NOT_IN(expressions ...Expression) BoolExpression
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// The temporary alias name to assign to the expression
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AS(alias string) projection
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// Expression will be used to sort query result in ascending order
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ASC() OrderByClause
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// Expression will be used to sort query result in ascending order
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DESC() OrderByClause
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// Cast expression to dbType
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TO(dbType string) Expression
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// Cast expression to bool type
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TO_BOOL() BoolExpression
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// Cast expression to smallint type
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TO_SMALLINT() IntegerExpression
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// Cast expression to integer type
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TO_INTEGER() IntegerExpression
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// Cast expression to bigint type
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TO_BIGINT() IntegerExpression
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// Cast expression to numeric type, using precision and optionally scale
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TO_NUMERIC(precision int, scale ...int) FloatExpression
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// Cast expression to real type
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TO_REAL() FloatExpression
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// Cast expression to double precision type
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TO_DOUBLE() FloatExpression
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// Cast expression to text type
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TO_TEXT() StringExpression
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// Cast expression to date type
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TO_DATE() DateExpression
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// Cast expression to time type
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TO_TIME() TimeExpression
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// Cast expression to time with time timezone type
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TO_TIMEZ() TimezExpression
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// Cast expression to timestamp type
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TO_TIMESTAMP() TimestampExpression
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// Cast expression to timestamp with timezone type
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TO_TIMESTAMPZ() TimestampzExpression
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}
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```
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Examples:
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```go
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Film.Description.IS_NULL()
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Int(1).ADD(Int(2)).AS("1+2")
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(Film.Duration.ADD(Int(3))).ASC()
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String("1999-01-08 13:05:06 +0100 CET").TO_TIMESTAMPZ()
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```
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## Comparision operators
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### Bool expression operators:
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```go
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type BoolExpression interface {
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Expression
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Jet supports following comparison operators for all expression types:
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// Check if this expression is equal to rhs
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EQ(rhs BoolExpression) BoolExpression
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// Check if this expression is not equal to rhs
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NOT_EQ(rhs BoolExpression) BoolExpression
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// Check if this expression is distinct to rhs
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IS_DISTINCT_FROM(rhs BoolExpression) BoolExpression
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// Check if this expression is not distinct to rhs
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IS_NOT_DISTINCT_FROM(rhs BoolExpression) BoolExpression
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| Method | Sample | Generated sql |
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| ------------------------------ | ------------------------------------------------ |---------------------------- |
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| EQ | jet.Int(1).EQ(table.Film.Length) | 1 = film.length |
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| NOT_EQ | jet.Int(1).EQ(table.Film.Length) | 1 != film.length |
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| IS_DISTINCT_FROM | jet.Int(1).IS_DISTINCT_FROM(table.Film.Length) | 1 IS DISTINCT FROM film.length |
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| IS_NOT_DISTINCT_FROM | jet.Int(1).IS_NOT_DISTINCT_FROM(table.Film.Length) | 1 IS NOT DISTINCT FROM film.length |
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| LT | jet.Int(1).LT(table.Film.Length) | 1 < film.length |
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| LT_EQ | jet.Int(1).LT_EQ(table.Film.Length) | 1 <= film.length |
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| GT | jet.Int(1).GT(table.Film.Length) | 1 > film.length |
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| GT_EQ | jet.Int(1).GT_EQ(table.Film.Length) | 1 >= film.length |
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// Check if this expression is true
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IS_TRUE() BoolExpression
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// Check if this expression is not true
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IS_NOT_TRUE() BoolExpression
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// Check if this expression is false
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IS_FALSE() BoolExpression
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// Check if this expression is not false
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IS_NOT_FALSE() BoolExpression
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// Check if this expression is unknown
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IS_UNKNOWN() BoolExpression
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// Check if this expression is not unknown
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IS_NOT_UNKNOWN() BoolExpression
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*Left-hand side and right-hand side of operators have to be of the same type*
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// expression AND operator rhs
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AND(rhs BoolExpression) BoolExpression
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// expression OR operator rhs
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OR(rhs BoolExpression) BoolExpression
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}
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```
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Examples:
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```
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Staff.Active.EQ(Bool(true))
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Staff.Active.IS_TRUE()
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## Arithmetic operators
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Bool(true).AND(Staff.Active).OR(Bool(false))
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```
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Following arithmetic operators are supported for integer and float expressions.
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If the first argument is float expression, second argument can be integer or float expression.
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If the first argument is integer expression second argument can only be integer expression.
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### Integer expression operators
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| Method | Sample | Generated sql |
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| ------------------------------ | ------------------------------------------------ |---------------------------- |
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| ADD | jet.Int(1).ADD(table.Film.Length) | 1 + film.length |
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| SUB | jet.Float(1.11).SUB(Int(1)) | 1.11 + 1 |
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| MUL | jet.Int(1).MUL(table.Film.Length) | 1 * film.length |
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| DIV | jet.Float(1.11).DIV(jet.Float(3.33) | 1.11 / 3.33 |
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| MOD | jet.Int(10).MOD(table.Film.Length) | 10 % film.length |
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| POW | jet.Float(10.01).POW(table.Film.Length) | 10.01 ^ film.length |
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```go
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type IntegerExpression interface {
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Expression
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numericExpression
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// Check if expression is equal to rhs
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EQ(rhs IntegerExpression) BoolExpression
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// Check if expression is not equal to rhs
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NOT_EQ(rhs IntegerExpression) BoolExpression
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// Check if expression is distinct from rhs
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IS_DISTINCT_FROM(rhs IntegerExpression) BoolExpression
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// Check if expression is not distinct from rhs
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IS_NOT_DISTINCT_FROM(rhs IntegerExpression) BoolExpression
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## Bit operators
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// Check if expression is less then rhs
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LT(rhs IntegerExpression) BoolExpression
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// Check if expression is less then equal rhs
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LT_EQ(rhs IntegerExpression) BoolExpression
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// Check if expression is greater then rhs
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GT(rhs IntegerExpression) BoolExpression
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// Check if expression is greater then equal rhs
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GT_EQ(rhs IntegerExpression) BoolExpression
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Following operators are only available on integer expressions:
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// expression + rhs
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ADD(rhs IntegerExpression) IntegerExpression
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// expression - rhs
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SUB(rhs IntegerExpression) IntegerExpression
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// expression * rhs
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MUL(rhs IntegerExpression) IntegerExpression
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// expression / rhs
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DIV(rhs IntegerExpression) IntegerExpression
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// expression % rhs
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MOD(rhs IntegerExpression) IntegerExpression
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// expression ^ rhs
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POW(rhs IntegerExpression) IntegerExpression
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| Method | Sample | Generated sql |
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| ------------------------------ | ------------------------------------------------ |---------------------------- |
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| BIT_AND | jet.Int(11).BIT_AND(table.Film.Length) | 11 & film.length |
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| BIT_OR | jet.Int(11).BIT_OR(table.Film.Length) | 11 \| film.length |
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| BIT_XOR | jet.Int(11).BIT_XOR(table.Film.Length) | 11 # film.length |
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| BIT_NOT | jet.Int(11).BIT_NOT(table.Film.Length) | ~ 11 |
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| BIT_SHIFT_LEFT | jet.Int(11).BIT_SHIFT_LEFT(table.Film.Length) | 11 >> film.length |
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| BIT_SHIFT_RIGHT | jet.Int(11).BIT_SHIFT_RIGHT(table.Film.Length) | 11 >> film.length |
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## Logical operators
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Following operators are only available on boolean expressions:
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| Method | Sample | Generated sql |
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| ------------------------------ | ---------------------------------------------------------|---------------------------- |
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| IS_TRUE | table.Staff.Active.IS_TRUE() | staff.active IS TRUE |
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| IS_NOT_TRUE | (table.Staff.Active.AND(jet.Bool(true))).IS_NOT_TRUE() | (staff.active AND true) IS NOT TRUE |
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| IS_FALSE | jet.Bool(false).IS_FALSE() | false IS FALSE |
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| IS_NOT_FALSE | jet.Bool(true).IS_NOT_FALSE() | true IS NOT FALSE |
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| IS_UNKNOWN | table.Staff.Active.IS_UNKNOWN() | staff.active IS UNKNOWN |
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| IS_NOT_UNKNOWN | table.Staff.Active.IS_NOT_UNKNOWN() | staff.active IS NOT UNKNOWN |
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## String operators
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Following operators are only available on string expressions:
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| Method | Sample | Generated sql |
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| ------------------------------ | ---------------------------------------------------------|---------------------------- |
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| CONCAT | table.Film.Name.CONCAT(table.Film.Description) | film.name \|\| film.description |
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| LIKE | table.Film.Name.LIKE(String("%Wind%")) | film.name LIKE %Wind% |
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| NOT_LIKE | table.Film.Name.NOT_LIKE(String("%Wind%")) | staff.active NOT LIKE %Wind% |
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| SIMILAR_TO | table.Film.Name.SIMILAR_TO(String("%Wind%")) | staff.active SIMILAR TO %Wind% |
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| NOT_SIMILAR_TO | table.Film.Name.NOT_SIMILAR_TO(String("%Wind%")) | staff.active NOT SIMILAR TO %Wind% |
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## Cast operators
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Cast operators allow expressions to be casted to some other database type.
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SQL builder expression type changes accordingly to database type.
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| Method | Sample | Generated sql |
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| ------------------------------ | -------------------------------------------|---------------------------- |
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| TO_BOOL | table.Film.Description.TO_BOOL() | film.description::boolean |
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| TO_SMALLINT | table.Film.Description.TO_SMALLINT() | film.description::smallint |
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| TO_INTEGER | table.Film.Description.TO_INTEGER() | film.description::integer |
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| TO_BIGINT | table.Film.Description.TO_BIGINT() | film.description::bigint |
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| TO_NUMERIC | table.Film.Description.TO_NUMERIC(10, 6) | film.description::numeric(10,6) |
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| TO_REAL | table.Film.Description.TO_REAL() | film.description::real |
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| TO_DOUBLE | table.Film.Description.TO_DOUBLE() | film.description::double |
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| TO_TEXT | table.Film.Description.TO_TEXT() | film.description::text |
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| TO_DATE | table.Film.Description.TO_DATE() | film.description::date |
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| TO_TIME | table.Film.Description.TO_TIME() | film.description::time |
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| TO_TIMEZ | table.Film.Description.TO_TIMEZ() | film.description::timez |
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| TO_TIMESTAMP | table.Film.Description.TO_TIMESTAMP() | film.description::timestamp |
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| TO_TIMESTAMPZ | table.Film.Description.TO_TIMESTAMPZ() | film.description::timestampz |
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// expression & rhs
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BIT_AND(rhs IntegerExpression) IntegerExpression
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// expression | rhs
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BIT_OR(rhs IntegerExpression) IntegerExpression
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// expression # rhs
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BIT_XOR(rhs IntegerExpression) IntegerExpression
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// ~expression
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BIT_NOT() IntegerExpression
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// expression << rhs
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BIT_SHIFT_LEFT(shift IntegerExpression) IntegerExpression
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// expression >> rhs
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BIT_SHIFT_RIGHT(shift IntegerExpression) IntegerExpression
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}
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```
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Examples:
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```go
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(Film.Length.ADD(Int(20))).LT(Int(200))
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Film.LanguageID.EQ(Int(2))
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Film.LanguageID.BIT_SHIFT_LEFT(Int(2))
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```
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