forked from mirror/gorm
60 lines
1.1 KiB
Go
60 lines
1.1 KiB
Go
package clause
|
|
|
|
// Select select attrs when querying, updating, creating
|
|
type Select struct {
|
|
Distinct bool
|
|
Columns []Column
|
|
Expression Expression
|
|
}
|
|
|
|
func (s Select) Name() string {
|
|
return "SELECT"
|
|
}
|
|
|
|
func (s Select) Build(builder Builder) {
|
|
if len(s.Columns) > 0 {
|
|
if s.Distinct {
|
|
builder.WriteString("DISTINCT ")
|
|
}
|
|
|
|
for idx, column := range s.Columns {
|
|
if idx > 0 {
|
|
builder.WriteByte(',')
|
|
}
|
|
builder.WriteQuoted(column)
|
|
}
|
|
} else {
|
|
builder.WriteByte('*')
|
|
}
|
|
}
|
|
|
|
func (s Select) MergeClause(clause *Clause) {
|
|
if s.Expression != nil {
|
|
if s.Distinct {
|
|
if expr, ok := s.Expression.(Expr); ok {
|
|
expr.SQL = "DISTINCT " + expr.SQL
|
|
clause.Expression = expr
|
|
return
|
|
}
|
|
}
|
|
|
|
clause.Expression = s.Expression
|
|
} else {
|
|
clause.Expression = s
|
|
}
|
|
}
|
|
|
|
// CommaExpression represents a group of expressions separated by commas.
|
|
type CommaExpression struct {
|
|
Exprs []Expression
|
|
}
|
|
|
|
func (comma CommaExpression) Build(builder Builder) {
|
|
for idx, expr := range comma.Exprs {
|
|
if idx > 0 {
|
|
_, _ = builder.WriteString(", ")
|
|
}
|
|
expr.Build(builder)
|
|
}
|
|
}
|