Add support for ... ALTER COLUMN ... DROP DEFAULT (#1532)

Author: manticore-projects

README.md

@@ -54,6 +54,8 @@ Also I would like to know about needed examples or documentation stuff.
 
 ## Extensions in the latest SNAPSHOT version 4.5
 
+- Add support for `... ALTER COLUMN ... DROP DEFAULT`
+
 Additionally, we have fixed many errors and improved the code quality and the test coverage.
 
 ## Extensions of JSqlParser releases

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

@@ -40,6 +40,8 @@ public class AlterExpression {
   private List<ColumnDataType> colDataTypeList;
   private List<ColumnDropNotNull> columnDropNotNullList;
 
+  private List<ColumnDropDefault> columnDropDefaultList;
+
   private List<String> pkColumns;
   private List<String> ukColumns;
   private String ukName;
@@ -239,6 +241,13 @@ public void addColDropNotNull(ColumnDropNotNull columnDropNotNull) {
     columnDropNotNullList.add(columnDropNotNull);
   }
 
+  public void addColDropDefault(ColumnDropDefault columnDropDefault) {
+    if (columnDropDefaultList == null) {
+      columnDropDefaultList = new ArrayList<>();
+    }
+    columnDropDefaultList.add(columnDropDefault);
+  }
+
   public List<String> getFkSourceColumns() {
     return fkSourceColumns;
   }
@@ -425,20 +434,11 @@ public String toString() {
             b.append(")");
           }
         } else if (getColumnDropNotNullList() != null) {
-          if (operation == AlterOperation.CHANGE) {
-            if (optionalSpecifier != null) {
-              b.append(optionalSpecifier).append(" ");
-            }
-            b.append(columnOldName).append(" ");
-          } else if (columnDropNotNullList.size() > 1) {
-            b.append("(");
-          } else {
-            b.append("COLUMN ");
-          }
+          b.append("COLUMN ");
           b.append(PlainSelect.getStringList(columnDropNotNullList));
-          if (columnDropNotNullList.size() > 1) {
-            b.append(")");
-          }
+        } else if ( columnDropDefaultList != null && !columnDropDefaultList.isEmpty() ) {
+          b.append("COLUMN ");
+          b.append(PlainSelect.getStringList(columnDropDefaultList));
         } else if (constraintName != null) {
           b.append("CONSTRAINT ");
           if (usingIfExists) {
@@ -731,4 +731,22 @@ public String toString() {
       return columnName + " DROP" + (withNot ? " NOT " : " ") + "NULL";
     }
   }
+
+  public static final class ColumnDropDefault {
+
+    private final String columnName;
+
+    public ColumnDropDefault(String columnName) {
+      this.columnName = columnName;
+    }
+
+    public String getColumnName() {
+      return columnName;
+    }
+
+    @Override
+    public String toString() {
+      return columnName + " DROP DEFAULT";
+    }
+  }
 }

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

@@ -5494,6 +5494,21 @@ AlterExpression.ColumnDropNotNull AlterExpressionColumnDropNotNull():
     }
 }
 
+AlterExpression.ColumnDropDefault AlterExpressionColumnDropDefault():
+{
+    String columnName = null;
+    boolean withNot = false;
+    ColDataType dataType = null;
+    List<String> columnSpecs = null;
+    List<String> parameter = null;
+}
+{
+    columnName = RelObjectName() <K_DROP> <K_DEFAULT>
+    {
+        return new AlterExpression.ColumnDropDefault(columnName);
+    }
+}
+
 List<ConstraintState> AlterExpressionConstraintState():
 {
     List<ConstraintState> retval = new ArrayList<ConstraintState>();
@@ -5549,6 +5564,7 @@ AlterExpression AlterExpression():
     Table fkTable = null;
     AlterExpression.ColumnDataType alterExpressionColumnDataType = null;
     AlterExpression.ColumnDropNotNull alterExpressionColumnDropNotNull = null;
+    AlterExpression.ColumnDropDefault alterExpressionColumnDropDefault = null;
     ReferentialAction.Action action = null;
 
     // for captureRest()
@@ -5576,10 +5592,22 @@ AlterExpression AlterExpression():
               [<K_USING> sk4=RelObjectName() { alterExp.addParameters("USING", sk4); }]
             )
                     |
-            LOOKAHEAD(3) ( (LOOKAHEAD(2) <K_COLUMN> { alterExp.hasColumn(true); })?
-                (LOOKAHEAD(2) alterExpressionColumnDataType = AlterExpressionColumnDataType() { alterExp.addColDataType(alterExpressionColumnDataType); }
-                |
-                alterExpressionColumnDropNotNull = AlterExpressionColumnDropNotNull() { alterExp.addColDropNotNull( alterExpressionColumnDropNotNull); })
+            LOOKAHEAD(3) (
+                ( LOOKAHEAD(2) <K_COLUMN> { alterExp.hasColumn(true); } )?
+
+                (
+                    LOOKAHEAD(2) alterExpressionColumnDataType = AlterExpressionColumnDataType() {
+                            alterExp.addColDataType(alterExpressionColumnDataType);
+                         }
+                    |
+                    LOOKAHEAD(3) alterExpressionColumnDropNotNull = AlterExpressionColumnDropNotNull() {
+                            alterExp.addColDropNotNull( alterExpressionColumnDropNotNull);
+                         }
+                    |
+                    alterExpressionColumnDropDefault = AlterExpressionColumnDropDefault() {
+                            alterExp.addColDropDefault( alterExpressionColumnDropDefault);
+                         }
+                )
             )
             |
             (

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

@@ -131,22 +131,22 @@ public void testAlterTableAddUniqueConstraint() throws JSQLParserException {
     }
 
     @Test
-    public void testAlterTableForgeignKey2() throws JSQLParserException {
+    public void testAlterTableForeignKey2() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE test ADD FOREIGN KEY (user_id) REFERENCES ra_user (id)");
     }
 
     @Test
-    public void testAlterTableForgeignKey3() throws JSQLParserException {
+    public void testAlterTableForeignKey3() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE test ADD FOREIGN KEY (user_id) REFERENCES ra_user (id) ON DELETE RESTRICT");
     }
 
     @Test
-    public void testAlterTableForgeignKey4() throws JSQLParserException {
+    public void testAlterTableForeignKey4() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE test ADD FOREIGN KEY (user_id) REFERENCES ra_user (id) ON DELETE SET NULL");
     }
 
     @Test
-    public void testAlterTableForgeignWithFkSchema() throws JSQLParserException {
+    public void testAlterTableForeignWithFkSchema() throws JSQLParserException {
         final String FK_SCHEMA_NAME = "my_schema";
         final String FK_TABLE_NAME = "ra_user";
         String sql = "ALTER TABLE test ADD FOREIGN KEY (user_id) REFERENCES " + FK_SCHEMA_NAME + "." + FK_TABLE_NAME + " (id) ON DELETE SET NULL";
@@ -776,4 +776,12 @@ public void testAlterTableChangeColumnDropNotNull() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY (COLUMN b DROP NOT NULL, COLUMN c DROP NOT NULL)", true);
     }
 
+    @Test
+    public void testAlterTableChangeColumnDropDefault() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY COLUMN b DROP DEFAULT", true);
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY (COLUMN b DROP DEFAULT, COLUMN c DROP DEFAULT)", true);
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY (COLUMN b DROP NOT NULL, COLUMN b DROP DEFAULT)", true);
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY (COLUMN b DROP DEFAULT, COLUMN b DROP NOT NULL)", true);
+    }
+
 }