feat: add UUID data type (#2036)

Author: olavloite

src/main/java/com/google/cloud/spanner/jdbc/JdbcDatabaseMetaData.java

@@ -1290,6 +1290,44 @@ public ResultSet getTypeInfo() {
                     .set("NUM_PREC_RADIX")
                     .to(10)
                     .build(),
+                Struct.newBuilder()
+                    .set("TYPE_NAME")
+                    .to("UUID")
+                    .set("DATA_TYPE")
+                    .to(Types.OTHER) // There's no JDBC-specific type code for UUID.
+                    .set("PRECISION")
+                    .to((Long) null)
+                    .set("LITERAL_PREFIX")
+                    .to("UUID ")
+                    .set("LITERAL_SUFFIX")
+                    .to((String) null)
+                    .set("CREATE_PARAMS")
+                    .to((String) null)
+                    .set("NULLABLE")
+                    .to(DatabaseMetaData.typeNullable)
+                    .set("CASE_SENSITIVE")
+                    .to(false)
+                    .set("SEARCHABLE")
+                    .to(DatabaseMetaData.typeSearchable)
+                    .set("UNSIGNED_ATTRIBUTE")
+                    .to(true)
+                    .set("FIXED_PREC_SCALE")
+                    .to(false)
+                    .set("AUTO_INCREMENT")
+                    .to(false)
+                    .set("LOCAL_TYPE_NAME")
+                    .to("UUID")
+                    .set("MINIMUM_SCALE")
+                    .to(0)
+                    .set("MAXIMUM_SCALE")
+                    .to(0)
+                    .set("SQL_DATA_TYPE")
+                    .to((Long) null)
+                    .set("SQL_DATETIME_SUB")
+                    .to((Long) null)
+                    .set("NUM_PREC_RADIX")
+                    .to((Long) null)
+                    .build(),
                 getJsonType(connection.getDialect()))),
         // Allow column 2 to be cast to short without any range checks.
         ImmutableSet.of(2));

src/main/resources/com/google/cloud/spanner/jdbc/DatabaseMetaData_GetColumns.sql

@@ -27,6 +27,8 @@ SELECT TABLE_CATALOG AS TABLE_CAT, TABLE_SCHEMA AS TABLE_SCHEM, TABLE_NAME, COLU
     WHEN SPANNER_TYPE LIKE 'STRING%' THEN -9
     WHEN SPANNER_TYPE = 'JSON' THEN -9
     WHEN SPANNER_TYPE = 'TIMESTAMP' THEN 93
+    WHEN SPANNER_TYPE = 'UUID' THEN 1111
+    ELSE 1111
   END AS DATA_TYPE,
   SPANNER_TYPE AS TYPE_NAME,
   CASE

src/test/java/com/google/cloud/spanner/jdbc/JdbcDatabaseMetaDataTest.java

@@ -510,6 +510,10 @@ public void testGetTypeInfo() throws SQLException {
         assertEquals(Types.NUMERIC, rs.getInt("DATA_TYPE"));
         assertEquals(Types.NUMERIC, rs.getShort("DATA_TYPE"));
         assertTrue(rs.next());
+        assertEquals("UUID", rs.getString("TYPE_NAME"));
+        assertEquals(Types.OTHER, rs.getInt("DATA_TYPE"));
+        assertEquals(Types.OTHER, rs.getShort("DATA_TYPE"));
+        assertTrue(rs.next());
         if (dialect == Dialect.POSTGRESQL) {
           assertEquals("JSONB", rs.getString("TYPE_NAME"));
           assertEquals(PgJsonbType.VENDOR_TYPE_NUMBER, rs.getInt("DATA_TYPE"));