Github user vdiravka commented on a diff in the pull request:
https://github.com/apache/drill/pull/541#discussion_r71585003
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/planner/sql/handlers/DropTableIfExistsHandler.java
---
@@ -28,47 +30,57 @@
import org.apache.drill.exec.physical.PhysicalPlan;
import org.apache.drill.exec.planner.sql.DirectPlan;
import org.apache.drill.exec.planner.sql.SchemaUtilites;
-import org.apache.drill.exec.planner.sql.parser.SqlDropTable;
+import org.apache.drill.exec.planner.sql.parser.SqlDropTableIfExists;
import org.apache.drill.exec.store.AbstractSchema;
// SqlHandler for dropping a table.
-public class DropTableHandler extends DefaultSqlHandler {
+public class DropTableIfExistsHandler extends DefaultSqlHandler {
- private static org.slf4j.Logger logger =
org.slf4j.LoggerFactory.getLogger(DropTableHandler.class);
+ private static org.slf4j.Logger logger =
org.slf4j.LoggerFactory.getLogger(DropTableIfExistsHandler.class);
- public DropTableHandler(SqlHandlerConfig config) {
+ public DropTableIfExistsHandler(SqlHandlerConfig config) {
super(config);
}
/**
- * Function resolves the schema and invokes the drop method. Raises an
exception if the schema is
- * immutable.
- * @param sqlNode - Table name identifier
- * @return - Single row indicating drop succeeded, raise exception
otherwise
+ * Function resolves the schema and invokes the drop method
+ * (while IF EXISTS statement is used function invokes the drop method
only if table exists).
+ * Raises an exception if the schema is immutable.
+ * @param sqlNode - SqlDropTableIfExists (SQL parse tree of drop table
[if exists] query)
+ * @return - Single row indicating drop succeeded or table is not found
while IF EXISTS statement is used,
+ * raise exception otherwise
* @throws ValidationException
* @throws RelConversionException
* @throws IOException
*/
@Override
public PhysicalPlan getPlan(SqlNode sqlNode) throws ValidationException,
RelConversionException, IOException {
- SqlDropTable dropTableNode = ((SqlDropTable) sqlNode);
- SqlIdentifier tableIdentifier = dropTableNode.getTableIdentifier();
+ SqlDropTableIfExists dropTableIfExistsNode = ((SqlDropTableIfExists)
sqlNode);
+ SqlIdentifier tableIdentifier =
dropTableIfExistsNode.getTableIdentifier();
SchemaPlus defaultSchema = config.getConverter().getDefaultSchema();
AbstractSchema drillSchema = null;
if (tableIdentifier != null) {
- drillSchema =
SchemaUtilites.resolveToMutableDrillSchema(defaultSchema,
dropTableNode.getSchema());
+ drillSchema =
SchemaUtilites.resolveToMutableDrillSchema(defaultSchema,
dropTableIfExistsNode.getSchema());
}
- String tableName = ((SqlDropTable) sqlNode).getName();
+ String tableName = dropTableIfExistsNode.getName();
if (drillSchema == null) {
throw UserException.validationError()
.message("Invalid table_name [%s]", tableName)
.build(logger);
}
+ if (dropTableIfExistsNode.checkTableExistence()) {
+ final Table tableToDrop =
SqlHandlerUtil.getTableFromSchema(drillSchema, tableName);
+ if (tableToDrop == null || tableToDrop.getJdbcTableType() !=
Schema.TableType.TABLE) {
--- End diff --
I checked such query `drop table if exists hbase.TestTableNullStr` and
found that the message is proper and same like for `DROP TABLE` statement:
`PARSE ERROR: Unable to create or drop tables/views. Schema [hbase] is
immutable.`.
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