--- /dev/null
+/*\r
+\r
+ Derby - Class org.apache.derby.impl.sql.compile.BaseColumnNode\r
+\r
+ Licensed to the Apache Software Foundation (ASF) under one or more\r
+ contributor license agreements. See the NOTICE file distributed with\r
+ this work for additional information regarding copyright ownership.\r
+ The ASF licenses this file to you under the Apache License, Version 2.0\r
+ (the "License"); you may not use this file except in compliance with\r
+ the License. You may obtain a copy of the License at\r
+\r
+ http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+ Unless required by applicable law or agreed to in writing, software\r
+ distributed under the License is distributed on an "AS IS" BASIS,\r
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+ See the License for the specific language governing permissions and\r
+ limitations under the License.\r
+\r
+ */\r
+\r
+package org.apache.derby.impl.sql.compile;\r
+\r
+import org.apache.derby.iapi.sql.dictionary.DataDictionary;\r
+\r
+import org.apache.derby.iapi.error.StandardException;\r
+import org.apache.derby.iapi.reference.SQLState;\r
+\r
+import org.apache.derby.iapi.types.DataTypeDescriptor;\r
+import org.apache.derby.iapi.sql.Row;\r
+\r
+import org.apache.derby.iapi.store.access.Qualifier;\r
+\r
+import org.apache.derby.impl.sql.compile.ExpressionClassBuilder;\r
+\r
+import org.apache.derby.iapi.services.compiler.MethodBuilder;\r
+import org.apache.derby.iapi.services.sanity.SanityManager;\r
+\r
+/**\r
+ * A BaseColumnNode represents a column in a base table. The parser generates a\r
+ * BaseColumnNode for each column reference. A column refercence could be a column in\r
+ * a base table, a column in a view (which could expand into a complex\r
+ * expression), or a column in a subquery in the FROM clause. By the time\r
+ * we get to code generation, all BaseColumnNodes should stand only for columns\r
+ * in base tables.\r
+ *\r
+ */\r
+\r
+public class BaseColumnNode extends ValueNode\r
+{\r
+ private String columnName;\r
+\r
+ /*\r
+ ** This is the user-specified table name. It will be null if the\r
+ ** user specifies a column without a table name. \r
+ */\r
+ private TableName tableName;\r
+\r
+ /**\r
+ * Initializer for when you only have the column name.\r
+ *\r
+ * @param columnName The name of the column being referenced\r
+ * @param tableName The qualification for the column\r
+ * @param dts DataTypeServices for the column\r
+ */\r
+\r
+ public void init(\r
+ Object columnName,\r
+ Object tableName,\r
+ Object dts) throws StandardException\r
+ {\r
+ this.columnName = (String) columnName;\r
+ this.tableName = (TableName) tableName;\r
+ setType((DataTypeDescriptor) dts);\r
+ }\r
+\r
+ /**\r
+ * Convert this object to a String. See comments in QueryTreeNode.java\r
+ * for how this should be done for tree printing.\r
+ *\r
+ * @return This object as a String\r
+ */\r
+\r
+ public String toString()\r
+ {\r
+ if (SanityManager.DEBUG)\r
+ {\r
+ return "columnName: " + columnName + "\n" +\r
+ ( ( tableName != null) ?\r
+ tableName.toString() :\r
+ "tableName: null\n") +\r
+ super.toString();\r
+ }\r
+ else\r
+ {\r
+ return "";\r
+ }\r
+ }\r
+\r
+ /**\r
+ * Get the name of this column\r
+ *\r
+ * @return The name of this column\r
+ */\r
+\r
+ public String getColumnName()\r
+ {\r
+ return columnName;\r
+ }\r
+\r
+ /**\r
+ * Get the user-supplied table name of this column. This will be null\r
+ * if the user did not supply a name (for example, select a from t).\r
+ * The method will return B for this example, select b.a from t as b\r
+ * The method will return T for this example, select t.a from t\r
+ *\r
+ * @return The user-supplied name of this column. Null if no user-\r
+ * supplied name.\r
+ */\r
+\r
+ public String getTableName()\r
+ {\r
+ return ( ( tableName != null) ? tableName.getTableName() : null );\r
+ }\r
+\r
+ /**\r
+ * Get the user-supplied schema name for this column's table. This will be null\r
+ * if the user did not supply a name (for example, select t.a from t).\r
+ * Another example for null return value (for example, select b.a from t as b).\r
+ * But for following query select app.t.a from t, this will return APP\r
+ *\r
+ * @return The schema name for this column's table\r
+ */\r
+ public String getSchemaName() throws StandardException\r
+ {\r
+ return ( ( tableName != null) ? tableName.getSchemaName() : null );\r
+ }\r
+\r
+ /**\r
+ * Do the code generation for this node. Should never be called.\r
+ *\r
+ * @param acb The ExpressionClassBuilder for the class being built\r
+ * @param mb The method the code to place the code\r
+ *\r
+ *\r
+ * @exception StandardException Thrown on error\r
+ */\r
+\r
+ public void generateExpression(ExpressionClassBuilder acb,\r
+ MethodBuilder mb)\r
+ throws StandardException\r
+ {\r
+ throw StandardException.newException(SQLState.LANG_UNABLE_TO_GENERATE,\r
+ this.nodeHeader());\r
+ }\r
+\r
+ /**\r
+ * Return the variant type for the underlying expression.\r
+ * The variant type can be:\r
+ * VARIANT - variant within a scan\r
+ * (method calls and non-static field access)\r
+ * SCAN_INVARIANT - invariant within a scan\r
+ * (column references from outer tables)\r
+ * QUERY_INVARIANT - invariant within the life of a query\r
+ * (constant expressions)\r
+ *\r
+ * @return The variant type for the underlying expression.\r
+ */\r
+ protected int getOrderableVariantType()\r
+ {\r
+ return Qualifier.SCAN_INVARIANT;\r
+ }\r
+ \r
+ /**\r
+ * {@inheritDoc}\r
+ */\r
+ protected boolean isEquivalent(ValueNode o)\r
+ {\r
+ if (isSameNodeType(o)) \r
+ {\r
+ BaseColumnNode other = (BaseColumnNode)o;\r
+ return other.tableName.equals(other.tableName) \r
+ && other.columnName.equals(columnName);\r
+ } \r
+ return false;\r
+ }\r
+}\r
projects / Benchmarks_CSolver.git / blobdiff