/
limit.go
48 lines (40 loc) · 999 Bytes
/
limit.go
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package clause
import "strconv"
// Limit limit clause
type Limit struct {
Limit *int
Offset int
}
// Name where clause name
func (limit Limit) Name() string {
return "LIMIT"
}
// Build build where clause
func (limit Limit) Build(builder Builder) {
if limit.Limit != nil && *limit.Limit >= 0 {
builder.WriteString("LIMIT ")
builder.WriteString(strconv.Itoa(*limit.Limit))
}
if limit.Offset > 0 {
if limit.Limit != nil && *limit.Limit >= 0 {
builder.WriteByte(' ')
}
builder.WriteString("OFFSET ")
builder.WriteString(strconv.Itoa(limit.Offset))
}
}
// MergeClause merge order by clauses
func (limit Limit) MergeClause(clause *Clause) {
clause.Name = ""
if v, ok := clause.Expression.(Limit); ok {
if (limit.Limit == nil || *limit.Limit == 0) && (v.Limit != nil && *v.Limit != 0) {
limit.Limit = v.Limit
}
if limit.Offset == 0 && v.Offset > 0 {
limit.Offset = v.Offset
} else if limit.Offset < 0 {
limit.Offset = 0
}
}
clause.Expression = limit
}