nodeLimit handles *tree.Limit nodes.
(ctx *Context, node *tree.Limit)
| 26 | |
| 27 | // nodeLimit handles *tree.Limit nodes. |
| 28 | func nodeLimit(ctx *Context, node *tree.Limit) (*vitess.Limit, error) { |
| 29 | if node == nil || ((node.Count == nil || node.Count == tree.NullLiteral{}) && (node.Offset == nil || node.Offset == tree.NullLiteral{})) { |
| 30 | return nil, nil |
| 31 | } |
| 32 | var count vitess.Expr |
| 33 | if !node.LimitAll { |
| 34 | var err error |
| 35 | count, err = nodeExpr(ctx, node.Count) |
| 36 | if err != nil { |
| 37 | return nil, err |
| 38 | } |
| 39 | } |
| 40 | offset, err := nodeExpr(ctx, node.Offset) |
| 41 | if err != nil { |
| 42 | return nil, err |
| 43 | } |
| 44 | // GMS is hardcoded to expect vitess.SQLVal for expressions such as `LIMIT 1 OFFSET 1`. |
| 45 | // We need to remove the hard dependency, but for now, we'll just convert our literals to a vitess.SQLVal. |
| 46 | if injectedExpr, ok := count.(vitess.InjectedExpr); ok { |
| 47 | if literal, ok := injectedExpr.Expression.(*expression.Literal); ok { |
| 48 | l := literal.Value() |
| 49 | limitValue, err := int64ValueForLimit(l) |
| 50 | if err != nil { |
| 51 | return nil, err |
| 52 | } |
| 53 | |
| 54 | if limitValue < 0 { |
| 55 | return nil, errors.Errorf("LIMIT must be greater than or equal to 0") |
| 56 | } |
| 57 | |
| 58 | count = pgexprs.ToVitessLiteral(literal) |
| 59 | } |
| 60 | } |
| 61 | if injectedExpr, ok := offset.(vitess.InjectedExpr); ok { |
| 62 | if literal, ok := injectedExpr.Expression.(*expression.Literal); ok { |
| 63 | o := literal.Value() |
| 64 | offsetVal, err := int64ValueForLimit(o) |
| 65 | if err != nil { |
| 66 | return nil, err |
| 67 | } |
| 68 | |
| 69 | if offsetVal < 0 { |
| 70 | return nil, errors.Errorf("OFFSET must be greater than or equal to 0") |
| 71 | } |
| 72 | |
| 73 | offset = pgexprs.ToVitessLiteral(literal) |
| 74 | } |
| 75 | } |
| 76 | return &vitess.Limit{ |
| 77 | Offset: offset, |
| 78 | Rowcount: count, |
| 79 | }, nil |
| 80 | } |
| 81 | |
| 82 | // int64ValueForLimit converts a literal value to an int64 |
| 83 | func int64ValueForLimit(l any) (int64, error) { |
no test coverage detected