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