51 lines
1.2 KiB
Go
51 lines
1.2 KiB
Go
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package mydb
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import "git.hexq.cn/tiglog/mydb/internal/adapter"
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// AndExpr represents an expression joined by a logical conjuction (AND).
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type AndExpr struct {
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*adapter.LogicalExprGroup
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}
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// And adds more expressions to the group.
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func (a *AndExpr) And(andConds ...LogicalExpr) *AndExpr {
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var fn func(*[]LogicalExpr) error
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if len(andConds) > 0 {
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fn = func(in *[]LogicalExpr) error {
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*in = append(*in, andConds...)
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return nil
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}
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}
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return &AndExpr{a.LogicalExprGroup.Frame(fn)}
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}
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// Empty returns false if the expressions has zero conditions.
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func (a *AndExpr) Empty() bool {
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return a.LogicalExprGroup.Empty()
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}
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// And joins conditions under logical conjunction. Conditions can be
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// represented by `db.Cond{}`, `db.Or()` or `db.And()`.
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//
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// Examples:
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//
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// // name = "Peter" AND last_name = "Parker"
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// db.And(
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// db.Cond{"name": "Peter"},
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// db.Cond{"last_name": "Parker "},
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// )
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//
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// // (name = "Peter" OR name = "Mickey") AND last_name = "Mouse"
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// db.And(
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// db.Or(
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// db.Cond{"name": "Peter"},
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// db.Cond{"name": "Mickey"},
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// ),
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// db.Cond{"last_name": "Mouse"},
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// )
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func And(conds ...LogicalExpr) *AndExpr {
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return &AndExpr{adapter.NewLogicalExprGroup(adapter.LogicalOperatorAnd, conds...)}
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}
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var _ = adapter.LogicalExpr(&AndExpr{})
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