Merge pull request #185 from schweighart/fix-alter-drop

Support for alter table drop column/constraint

Author: wumpz

src/main/java/net/sf/jsqlparser/statement/alter/Alter.java

@@ -42,6 +42,8 @@ public class Alter implements Statement {
     private List<String> ukColumns;
     private String ukName;
     private ForeignKeyIndex fkIndex = null;
+	private String operation;
+    private String constraintName;
 
     private boolean onDeleteCascade;
 
@@ -93,6 +95,14 @@ public void setFkSourceTable(String fkSourceTable) {
         this.fkSourceTable = fkSourceTable;
     }
 
+    public String getOperation() {
+        return operation;
+    }
+
+    public void setOperation(String operation) {
+        this.operation = operation;
+    }
+
     private List<String> fkSourceColumns;
 
     public List<String> getFkSourceColumns() {
@@ -119,6 +129,14 @@ public void setColumnName(String columnName) {
         this.columnName = columnName;
     }
 
+    public String getConstraintName() {
+        return this.constraintName;
+    }
+
+    public void setConstraintName(final String constraintName) {
+        this.constraintName = constraintName;
+    }
+
     public ColDataType getDataType() {
         return dataType;
     }
@@ -167,9 +185,14 @@ public void setFkIndex(ForeignKeyIndex fkIndex) {
     @Override
     public String toString() {
         StringBuilder b = new StringBuilder();
-        b.append("ALTER TABLE ").append(table.getFullyQualifiedName()).append(" ADD ");
+        b.append("ALTER TABLE ").append(table.getFullyQualifiedName()).append(" ").append(operation).append(" ");
         if (columnName != null) {
-            b.append("COLUMN ").append(columnName).append(" ").append(dataType.toString());
+            b.append("COLUMN ").append(columnName);
+            if (dataType != null) {
+                b.append(" ").append(dataType.toString());
+            }
+        } else if (constraintName != null) {
+            b.append("CONSTRAINT ").append(constraintName);
         } else if (pkColumns != null) {
             b.append("PRIMARY KEY (").append(PlainSelect.getStringList(pkColumns)).append(")");
         } else if (ukColumns != null) {

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -2773,13 +2773,16 @@ Alter Alter():
     List<String> columnNames = null;
     ForeignKeyIndex fkIndex = null;
     Table fkTable = null;
+    Token alterDrop = null;
 }
 {
 	<K_ALTER> <K_TABLE> table=Table() { alter.setTable(table); } 
-
-    <K_ADD> 
-    
-    (  
+    (
+    (alterDrop = <K_ADD>
+    	{
+    		alter.setOperation(alterDrop.image);
+    	}
+    	  (
         (  <K_COLUMN>
 	       (tk=<S_IDENTIFIER>	| tk=<S_QUOTED_IDENTIFIER>) dataType=ColDataType()
             {
@@ -2820,8 +2823,30 @@ Alter Alter():
                     alter.setFkIndex(fkIndex);
                 }
         )
+        )
+    )
+    |
+    (alterDrop = <K_DROP>
+      {
+    		alter.setOperation(alterDrop.image);
+    	}
+    	 (
+			 (  <K_COLUMN>
+			 (tk=<S_IDENTIFIER>	| tk=<S_QUOTED_IDENTIFIER>)
+					 {
+							alter.setColumnName(tk.image);
+					 }
+			 )
+			 |
+       (  <K_CONSTRAINT>
+       (tk=<S_IDENTIFIER>	| tk=<S_QUOTED_IDENTIFIER>)
+           {
+              alter.setConstraintName(tk.image);
+           }
+       )
+       )
+    )
     )
-
     {
 		return alter;
 	}

src/test/java/net/sf/jsqlparser/test/alter/AlterTest.java

@@ -50,4 +50,12 @@ public void testAlterTableForgeignKey3() throws JSQLParserException {
     public void testAlterTableForgeignKey4() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE test ADD FOREIGN KEY (user_id) REFERENCES ra_user (id) ON DELETE SET NULL");
     }
+
+    public void testAlterTableDropColumn() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN YYY");
+    }
+
+    public void testAlterTableDropConstraint() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP CONSTRAINT YYY");
+    }
 }