Add support for SQL "union" operator.

gk-brown · gk-brown · commit df1b890ee920 · 2021-07-18T08:24:52.000-04:00
diff --git a/httprpc-client/src/main/java/org/httprpc/sql/QueryBuilder.java b/httprpc-client/src/main/java/org/httprpc/sql/QueryBuilder.java
@@ -222,6 +222,22 @@ public QueryBuilder forUpdate() {
         return this;
     }
 
+    /**
+     * Appends a "union" clause to a query.
+     *
+     * @param queryBuilder
+     * The query builder to append.
+     *
+     * @return
+     * The {@link QueryBuilder} instance.
+     */
+    public QueryBuilder union(QueryBuilder queryBuilder) {
+        sqlBuilder.append(" union ");
+        sqlBuilder.append(queryBuilder.toString());
+
+        return this;
+    }
+
     /**
      * Creates an "insert into" query.
      *
@@ -272,7 +288,7 @@ public static QueryBuilder insertInto(String table, Map<String, ?> values) {
 
             if (value instanceof QueryBuilder) {
                 sqlBuilder.append("(");
-                sqlBuilder.append(value.toString());
+                sqlBuilder.append(value);
                 sqlBuilder.append(")");
             } else {
                 sqlBuilder.append(encode(value));
@@ -336,7 +352,7 @@ public QueryBuilder set(Map<String, ?> values) {
 
             if (value instanceof QueryBuilder) {
                 sqlBuilder.append("(");
-                sqlBuilder.append(value.toString());
+                sqlBuilder.append(value);
                 sqlBuilder.append(")");
             } else {
                 sqlBuilder.append(encode(value));
diff --git a/httprpc-client/src/test/java/org/httprpc/sql/QueryBuilderTest.java b/httprpc-client/src/test/java/org/httprpc/sql/QueryBuilderTest.java
@@ -31,7 +31,9 @@ public void testSelect() {
             .where("(a > 10 or b < 200) and c = :c")
             .orderBy("a", "b")
             .limit(10)
-            .forUpdate().toString();
+            .forUpdate()
+            .union(QueryBuilder.select("a", "b", "c")
+                .from("C")).toString();
 
         assertEquals("select a, b, c from A "
             + "join B on A.id = B.id and x = 50 "
@@ -40,7 +42,9 @@ public void testSelect() {
             + "where (a > 10 or b < 200) and c = :c "
             + "order by a, b "
             + "limit 10 "
-            + "for update", sql);
+            + "for update "
+            + "union "
+            + "select a, b, c from C", sql);
     }
 
     @Test
@@ -74,8 +78,7 @@ public void testUpdate() {
     @Test
     public void testDelete() {
         String sql = QueryBuilder.deleteFrom("A")
-            .where("a < 150")
-            .toString();
+            .where("a < 150").toString();
 
         assertEquals("delete from A where a < 150", sql);
     }
