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Additional documentation.

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This commit is contained in:
go-jet 2019-07-18 17:43:11 +02:00
parent d253a35161
commit b10270b502
48 changed files with 892 additions and 699 deletions
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22
operators.go
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@ -4,17 +4,19 @@ import "errors"
//----------- Logical operators ---------------//
// Returns negation of bool expression expr
// NOT returns negation of bool expression result
func NOT(exp BoolExpression) BoolExpression {
return newPrefixBoolOperator(exp, "NOT")
}
// BIT_NOT inverts every bit in integer expression result
func BIT_NOT(expr IntegerExpression) IntegerExpression {
return newPrefixIntegerOperator(expr, "~")
}
//----------- Comparison operators ---------------//
// EXISTS checks for existence of the rows in subQuery
func EXISTS(subQuery SelectStatement) BoolExpression {
return newPrefixBoolOperator(subQuery, "EXISTS")
}
@ -59,12 +61,13 @@ func gtEq(lhs, rhs Expression) BoolExpression {
// --------------- CASE operator -------------------//
type CaseOperatorExpression interface {
// CaseOperator is interface for SQL case operator
type CaseOperator interface {
Expression
WHEN(condition Expression) CaseOperatorExpression
THEN(then Expression) CaseOperatorExpression
ELSE(els Expression) CaseOperatorExpression
WHEN(condition Expression) CaseOperator
THEN(then Expression) CaseOperator
ELSE(els Expression) CaseOperator
}
type caseOperatorImpl struct {
@ -76,7 +79,8 @@ type caseOperatorImpl struct {
els Expression
}
func CASE(expression ...Expression) CaseOperatorExpression {
// CASE create CASE operator with optional list of expressions
func CASE(expression ...Expression) CaseOperator {
caseExp := &caseOperatorImpl{}
if len(expression) > 0 {
@ -88,17 +92,17 @@ func CASE(expression ...Expression) CaseOperatorExpression {
return caseExp
}
func (c *caseOperatorImpl) WHEN(when Expression) CaseOperatorExpression {
func (c *caseOperatorImpl) WHEN(when Expression) CaseOperator {
c.when = append(c.when, when)
return c
}
func (c *caseOperatorImpl) THEN(then Expression) CaseOperatorExpression {
func (c *caseOperatorImpl) THEN(then Expression) CaseOperator {
c.then = append(c.then, then)
return c
}
func (c *caseOperatorImpl) ELSE(els Expression) CaseOperatorExpression {
func (c *caseOperatorImpl) ELSE(els Expression) CaseOperator {
c.els = els
return c