jet/internal/jet/cast.go
2019-08-12 10:16:08 +02:00

89 lines
1.8 KiB
Go

package jet
import "strconv"
type Cast interface {
AS(castType string) Expression
AS_CHAR(lenght ...int) StringExpression
// Cast expression AS date type
AS_DATE() DateExpression
// Cast expression AS numeric type, using precision and optionally scale
AS_DECIMAL() FloatExpression
// Cast expression AS time type
AS_TIME() TimeExpression
}
type CastImpl struct {
expression Expression
}
func NewCastImpl(expression Expression) Cast {
castImpl := CastImpl{
expression: expression,
}
return &castImpl
}
func (b *CastImpl) AS(castType string) Expression {
castExp := &castExpression{
expression: b.expression,
cast: string(castType),
}
castExp.ExpressionInterfaceImpl.Parent = castExp
return castExp
}
func (b *CastImpl) AS_CHAR(lenght ...int) StringExpression {
if len(lenght) > 0 {
return StringExp(b.AS("CHAR(" + strconv.Itoa(lenght[0]) + ")"))
}
return StringExp(b.AS("CHAR"))
}
// Cast expression AS date type
func (b *CastImpl) AS_DATE() DateExpression {
return DateExp(b.AS("DATE"))
}
// Cast expression AS date type
func (b *CastImpl) AS_DECIMAL() FloatExpression {
return FloatExp(b.AS("DECIMAL"))
}
// Cast expression AS date type
func (b *CastImpl) AS_TIME() TimeExpression {
return TimeExp(b.AS("TIME"))
}
type castExpression struct {
ExpressionInterfaceImpl
expression Expression
cast string
}
func (b *castExpression) serialize(statement StatementType, out *SqlBuilder, options ...SerializeOption) error {
expression := b.expression
castType := b.cast
if castOverride := out.Dialect.SerializeOverride("CAST"); castOverride != nil {
return castOverride(expression, String(castType))(statement, out, options...)
}
out.WriteString("CAST(")
err := expression.serialize(statement, out, options...)
if err != nil {
return err
}
out.WriteString("AS")
out.WriteString(castType + ")")
return err
}