Merge pull request #868 from Altinity/866-incorrect-precision-and-scale-parsing-due-to-column-comment-interference

866 incorrect precision and scale parsing due to column comment interference

Author: subkanthi

sink-connector-lightweight/src/main/java/com/altinity/clickhouse/debezium/embedded/ddl/parser/MySqlDDLParserListenerImpl.java

@@ -378,9 +378,10 @@ private String getClickHouseDataType(String parsedDataType, ParseTree colDefTree
             // Dont try to get precision/scale for enums
         }
         else if(parsedDataType.contains("(") && parsedDataType.contains(")") && parsedDataType.contains(",") ) {
+            String sanitizedDataType = parsedDataType.split("COMMENT")[0].trim();
             try {
-                precision = Integer.parseInt(parsedDataType.substring(parsedDataType.indexOf("(") + 1, parsedDataType.indexOf(",")));
-                scale = Integer.parseInt(parsedDataType.substring(parsedDataType.indexOf(",") + 1, parsedDataType.indexOf(")")));
+                precision = Integer.parseInt(sanitizedDataType.substring(sanitizedDataType.indexOf("(") + 1, sanitizedDataType.indexOf(",")));
+                scale = Integer.parseInt(sanitizedDataType.substring(sanitizedDataType.indexOf(",") + 1, sanitizedDataType.indexOf(")")));
             } catch(Exception e) {
                 log.error("Error parsing precision, scale : columnName" + columnName);
             }
@@ -508,7 +509,11 @@ else if(columnDefChild.getText().equalsIgnoreCase(Constants.NOT_NULL)) {
                         if (columnDefChild.getChildCount() >= 2) {
                             defaultModifier = "DEFAULT " + columnDefChild.getChild(1).getText();
                         }
-                    } else {
+                    } else if(columnDefChild instanceof MySqlParser.CommentColumnConstraintContext) {
+                        // Ignore comment for now.
+                        //commentModifier = columnDefChild.getChild(1).getText();
+                    }
+                    else   {
                         columnType = (columnDefChild.getText());
                         String chDataType = getClickHouseDataType(columnType, columnChild, columnName);
                         if (chDataType != null) {

sink-connector-lightweight/src/test/java/com/altinity/clickhouse/debezium/embedded/ddl/parser/MySqlDDLParserListenerImplTest.java

@@ -790,6 +790,26 @@ public void alterTableRenameTable() {
         Assert.assertTrue(clickHouseQuery.toString().equalsIgnoreCase("RENAME TABLE employees.test_table to employees.test_table_new"));
     }
 
+    @Test
+    public void testAlterTableColumnWithComment() {
+        StringBuffer clickHouseQuery = new StringBuffer();
+
+        String sql = "ALTER TABLE test_table ADD COLUMN col1 varchar(255) COMMENT 'test column';";
+        mySQLDDLParserService.parseSql(sql, "", clickHouseQuery);
+
+        Assert.assertTrue(clickHouseQuery.toString().equalsIgnoreCase("ALTER TABLE employees.test_table ADD COLUMN col1 Nullable(String)"));
+    }
+
+    @Test
+    public void testAlterTableColumnWithCommentAndDecimalScale() {
+        StringBuffer clickHouseQuery = new StringBuffer();
+
+        String sql = "ALTER TABLE test_table ADD COLUMN col1 decimal(10,2) COMMENT 'test column';";
+        mySQLDDLParserService.parseSql(sql, "", clickHouseQuery);
+
+        Assert.assertTrue(clickHouseQuery.toString().equalsIgnoreCase("ALTER TABLE employees.test_table ADD COLUMN col1 Nullable(Decimal(10,2))"));
+    }
+
     @Test
     public void testGeneratedColumn() {
         StringBuffer clickHouseQuery = new StringBuffer();