Support "ANY" with an array of values

This commit adds the ability to use "ANY(...Array)" to look up for a
value matching against an array.

For example:

dbz.Select("id").From("table").Where(ANY("id",[]int{1,2,3,4,5}))

We added that support in order to workaround a limitation of postgres of
maximum parameters in IN condition ("PostgreSQL only supports 65535 parameters").

Author: Chen Cohen

select_test.go

@@ -53,9 +53,10 @@ func TestSelect(t *testing.T) {
 
 			{
 				"select with array comparisons",
-				dbz.Select("*").From("table").Where(EqAny("array_col", 3), GtAll("other_array_col", 1), NeAny("yet_another_col", Indirect("NOW()"))),
-				"SELECT * FROM table WHERE ? = ANY(array_col) AND ? > ALL(other_array_col) AND NOW() <> ANY(yet_another_col)",
-				[]interface{}{3, 1},
+				dbz.Select("*").From("table").Where(EqAny("array_col", 3), GtAll("other_array_col", 1), NeAny("yet_another_col", Indirect("NOW()")),
+					Any(Indirect("column"),[]int{1,2,3})),
+				"SELECT * FROM table WHERE ? = ANY(array_col) AND ? > ALL(other_array_col) AND NOW() <> ANY(yet_another_col) AND column = ANY(?)",
+				[]interface{}{3, 1 ,"'{1,2,3}'"},
 			},
 
 			{

sqlz.go

@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"fmt"
 	"sort"
+	"strconv"
 	"strings"
 
 	"github.com/jmoiron/sqlx"
@@ -305,6 +306,12 @@ type ArrayCondition struct {
 	Right    interface{}
 }
 
+// Any creates an "ANY (array)" condition, to lookup for a value matching against an array of possible values
+// as similar to IN condition
+func Any(arr interface{}, value interface{}) ArrayCondition {
+	return ArrayCondition{arr, "=", "ANY", value}
+}
+
 // EqAny creates an "= ANY" condition on an array column
 func EqAny(arr interface{}, value interface{}) ArrayCondition {
 	return ArrayCondition{value, "=", "ANY", arr}
@@ -399,22 +406,28 @@ func (cond SQLCondition) Parse() (asSQL string, bindings []interface{}) {
 // Parse implements the WhereCondition interface, generating SQL from
 // the condition
 func (array ArrayCondition) Parse() (asSQL string, bindings []interface{}) {
-	var rightAsSQL, leftAsSQL string
+	rightAsSQL := "?"
+	leftAsSQL := "?"
 
 	if indirect, isIndirect := array.Left.(IndirectValue); isIndirect {
 		leftAsSQL = indirect.Reference
 		bindings = append(bindings, indirect.Bindings...)
 	} else {
-		leftAsSQL = "?"
 		bindings = append(bindings, array.Left)
 	}
 
-	switch array.Right.(type) {
+	switch right := array.Right.(type) {
 	case string:
 		rightAsSQL = fmt.Sprintf("%v", array.Right)
-	default:
-		rightAsSQL = "?"
+	case []int:
+		var values []string
+		for _, n := range right {
+			values = append(values, strconv.Itoa(n))
+		}
 
+		binds := fmt.Sprintf("'{%s}'", strings.Join(values, ","))
+		bindings = append(bindings, binds)
+	default:
 		bindings = append(bindings, array.Right)
 	}