Add a 'ArrayContains' operator ('@>' in PG)

database/array_contains.go

+package database
+
+import (
+	"database/sql/driver"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/jackc/pgtype"
+)
+
+type ArrayContains map[string]interface{}
+
+func (ac ArrayContains) ToSQL() (sql string, args []interface{}, err error) {
+	if len(ac) == 0 {
+		// Empty Sql{} evaluates to true.
+		sql = "(1=1)"
+		return
+	}
+
+	sortedKeys := getSortedKeys(ac)
+	var exprs []string
+
+	for _, key := range sortedKeys {
+		var expr string
+		val := ac[key]
+
+		switch v := val.(type) {
+		case driver.Valuer:
+			if val, err = v.Value(); err != nil {
+				return
+			}
+		case []string:
+			var data pgtype.TextArray
+			if err = data.Set(v); err != nil {
+				return
+			}
+			if val, err = data.Value(); err != nil {
+				return
+			}
+		case string:
+			var data pgtype.TextArray
+			if err = data.Set([]string{v}); err != nil {
+				return
+			}
+			if val, err = data.Value(); err != nil {
+				return
+			}
+		}
+		if val == nil {
+			panic("cannot handle NULL values")
+		} else {
+			expr = fmt.Sprintf("%s @> ?", key)
+			args = append(args, val)
+		}
+		exprs = append(exprs, expr)
+	}
+
+	sql = strings.Join(exprs, " AND ")
+	return
+}
+
+func getSortedKeys(exp map[string]interface{}) []string {
+	sortedKeys := make([]string, 0, len(exp))
+	for k := range exp {
+		sortedKeys = append(sortedKeys, k)
+	}
+	sort.Strings(sortedKeys)
+	return sortedKeys
+}

scripts/generate_db_helpers.go

@@ -344,6 +344,10 @@
 	return squirrel.NotLike{c.Sql(): value}
 }
 
+func (c Column) ArrayContains(value interface{}) database.ArrayContains{
+	return database.ArrayContains{c.Sql(): value}
+}
+
 func (c Column) As(name string) Column {
 	c.alias = name
 	return c