feat: add WithPgPlaceholder() option

Author: jimlambrt

mql.go

@@ -18,7 +18,8 @@ type WhereClause struct {
 }
 
 // Parse will parse the query and use the provided database model to create a
-// where clause. Supported options: WithColumnMap, WithIgnoreFields
+// where clause. Supported options: WithColumnMap, WithIgnoreFields,
+// WithConverter, WithPgPlaceholder
 func Parse(query string, model any, opt ...Option) (*WhereClause, error) {
 	const op = "mql.Parse"
 	switch {
@@ -40,6 +41,16 @@ func Parse(query string, model any, opt ...Option) (*WhereClause, error) {
 	if err != nil {
 		return nil, fmt.Errorf("%s: %w", op, err)
 	}
+	opts, err := getOpts(opt...)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", op, err)
+	}
+	if opts.withPgPlaceholder {
+		for i := 0; i < len(e.Args); i++ {
+			placeholder := fmt.Sprintf("$%d", i+1)
+			e.Condition = strings.Replace(e.Condition, "?", placeholder, 1)
+		}
+	}
 	return e, nil
 }
 

mql_test.go

@@ -66,6 +66,16 @@ func TestParse(t *testing.T) {
 				Args:      []any{"%alice%"},
 			},
 		},
+		{
+			name:  "success-WithPgPlaceholder",
+			query: "name=bob or (name%alice or name=eve)",
+			model: testModel{},
+			opts:  []mql.Option{mql.WithPgPlaceholders()},
+			want: &mql.WhereClause{
+				Condition: "(name=$1 or (name like $2 or name=$3))",
+				Args:      []any{"bob", "%alice%", "eve"},
+			},
+		},
 		{
 			name:            "err-leftExpr-without-op",
 			query:           "age (name=alice)",

options.go

@@ -13,6 +13,7 @@ type options struct {
 	withValidateConvertFn     ValidateConvertFunc
 	withValidateConvertColumn string
 	withIgnoredFields         []string
+	withPgPlaceholder         bool
 }
 
 // Option - how options are passed as args
@@ -91,3 +92,13 @@ func WithIgnoredFields(fieldName ...string) Option {
 		return nil
 	}
 }
+
+// WithPgPlaceholders will use parameters placeholders that are compatible with
+// the postgres pg driver which requires a placeholder like $1 instead of ?.
+// See: https://pkg.go.dev/github.com/lib/pq
+func WithPgPlaceholders() Option {
+	return func(o *options) error {
+		o.withPgPlaceholder = true
+		return nil
+	}
+}