mirror of https://github.com/go-gorm/gorm.git
83 lines
1.5 KiB
Go
83 lines
1.5 KiB
Go
package clause
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// From from clause
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type From struct {
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Tables []Table
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Joins []Join
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}
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type JoinType string
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const (
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CrossJoin JoinType = "CROSS"
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InnerJoin = "INNER"
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LeftJoin = "LEFT"
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RightJoin = "RIGHT"
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)
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// Join join clause for from
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type Join struct {
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Type JoinType
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Table Table
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ON Where
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Using []string
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}
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// Name from clause name
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func (from From) Name() string {
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return "FROM"
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}
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// Build build from clause
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func (from From) Build(builder Builder) {
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if len(from.Tables) > 0 {
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for idx, table := range from.Tables {
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if idx > 0 {
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builder.WriteByte(',')
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}
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builder.WriteQuoted(table)
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}
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} else {
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builder.WriteQuoted(currentTable)
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}
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for _, join := range from.Joins {
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builder.WriteByte(' ')
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join.Build(builder)
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}
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}
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func (join Join) Build(builder Builder) {
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if join.Type != "" {
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builder.WriteString(string(join.Type))
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builder.WriteByte(' ')
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}
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builder.WriteString("JOIN ")
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builder.WriteQuoted(join.Table)
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if len(join.ON.Exprs) > 0 {
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builder.WriteString(" ON ")
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join.ON.Build(builder)
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} else if len(join.Using) > 0 {
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builder.WriteString(" USING (")
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for idx, c := range join.Using {
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if idx > 0 {
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builder.WriteByte(',')
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}
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builder.WriteQuoted(c)
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}
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builder.WriteByte(')')
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}
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}
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// MergeClause merge from clause
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func (from From) MergeClause(clause *Clause) {
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if v, ok := clause.Expression.(From); ok {
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from.Tables = append(v.Tables, from.Tables...)
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from.Joins = append(v.Joins, from.Joins...)
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}
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clause.Expression = from
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}
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