AJ-455: optimize code logic for check duplicate colName.

Author: chengyitian

src/com/xxdb/data/BasicTable.java

@@ -132,7 +132,7 @@ public void replaceColName(String originalColName, String newColName) {
 		if (Utils.isEmpty(originalColName) || Utils.isEmpty(newColName))
 			throw new RuntimeException("The param 'newColName' cannot be null or empty.");
 
-		if (this.colNames.contains(newColName))
+		if (!this.colNames.contains(originalColName) && this.colNames.contains(newColName))
 			throw new RuntimeException("The newColName '" + newColName +"' already exists in table. Column names cannot be duplicated.");
 
 		if (this.colNames.contains(originalColName)) {