[#8650] Add support for MySQL's ALTER TABLE .. DROP PRIMARY KEY syntax

jOOQ/src/main/java/org/jooq/AlterTableStep.java

@@ -586,7 +586,14 @@ public interface AlterTableStep {
     AlterTableFinalStep dropConstraint(String constraint);
 
     /**
-     * Add a <code>DROP CONSTRAINT</code> clause to the <code>ALTER TABLE</code>
+     * Add a <code>DROP PRIMARY KEY</code> clause to the <code>ALTER TABLE</code>
+     * statement.
+     */
+    @Support({ MARIADB, MYSQL })
+    AlterTableFinalStep dropPrimaryKey();
+
+    /**
+     * Add a <code>DROP FOREIGN KEY</code> clause to the <code>ALTER TABLE</code>
      * statement.
      *
      * @see DSL#constraint(String)
@@ -595,7 +602,7 @@ public interface AlterTableStep {
     AlterTableFinalStep dropForeignKey(Constraint constraint);
 
     /**
-     * Add a <code>DROP CONSTRAINT</code> clause to the <code>ALTER TABLE</code>
+     * Add a <code>DROP FOREIGN KEY</code> clause to the <code>ALTER TABLE</code>
      * statement.
      *
      * @see DSL#constraint(String)
@@ -604,7 +611,7 @@ public interface AlterTableStep {
     AlterTableFinalStep dropForeignKey(Name constraint);
 
     /**
-     * Add a <code>DROP CONSTRAINT</code> clause to the <code>ALTER TABLE</code>
+     * Add a <code>DROP FOREIGN KEY</code> clause to the <code>ALTER TABLE</code>
      * statement.
      *
      * @see DSL#constraint(String)

jOOQ/src/main/java/org/jooq/impl/AlterTableImpl.java

@@ -71,6 +71,7 @@ import static org.jooq.SQLDialect.POSTGRES;
 // ...
 // ...
 import static org.jooq.impl.ConstraintType.FOREIGN_KEY;
+import static org.jooq.impl.ConstraintType.PRIMARY_KEY;
 import static org.jooq.impl.DSL.commentOnTable;
 import static org.jooq.impl.DSL.constraint;
 import static org.jooq.impl.DSL.field;
@@ -104,6 +105,7 @@ import static org.jooq.impl.Keywords.K_LIKE;
 import static org.jooq.impl.Keywords.K_MODIFY;
 import static org.jooq.impl.Keywords.K_NOT_NULL;
 import static org.jooq.impl.Keywords.K_NULL;
+import static org.jooq.impl.Keywords.K_PRIMARY_KEY;
 import static org.jooq.impl.Keywords.K_RAISE;
 import static org.jooq.impl.Keywords.K_RENAME;
 import static org.jooq.impl.Keywords.K_RENAME_COLUMN;
@@ -686,6 +688,12 @@ final class AlterTableImpl extends AbstractRowCountQuery implements
         return dropConstraint(DSL.constraint(constraint));
     }
 
+    @Override
+    public final AlterTableImpl dropPrimaryKey() {
+        dropConstraintType = PRIMARY_KEY;
+        return this;
+    }
+
     @Override
     public final AlterTableImpl dropForeignKey(Constraint constraint) {
         dropConstraint = constraint;
@@ -1271,6 +1279,11 @@ final class AlterTableImpl extends AbstractRowCountQuery implements
             ctx.data().remove(DATA_CONSTRAINT_REFERENCE);
             ctx.end(ALTER_TABLE_DROP);
         }
+        else if (dropConstraintType == PRIMARY_KEY) {
+            ctx.start(ALTER_TABLE_DROP);
+            ctx.visit(K_DROP).sql(' ').visit(K_PRIMARY_KEY);
+            ctx.end(ALTER_TABLE_DROP);
+        }
 
         if (!omitAlterTable)
             ctx.formatIndentEnd();

jOOQ/src/main/java/org/jooq/impl/ConstraintType.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Other licenses:
+ * -----------------------------------------------------------------------------
+ * Commercial licenses for this work are available. These replace the above
+ * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
+ * database integrations.
+ *
+ * For more information, please visit: http://www.jooq.org/licenses
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ */
+package org.jooq.impl;
+
+/**
+ * @author Lukas Eder
+ */
+enum ConstraintType {
+    PRIMARY_KEY,
+    UNIQUE,
+    FOREIGN_KEY,
+    CHECK
+}

jOOQ/src/main/java/org/jooq/impl/ParserImpl.java

@@ -3611,6 +3611,9 @@ final class ParserImpl implements Parser {
                     if (parseKeywordIf(ctx, "CONSTRAINT")) {
                         return s1.dropConstraint(parseIdentifier(ctx));
                     }
+                    else if (parseKeywordIf(ctx, "PRIMARY KEY")) {
+                        return s1.dropPrimaryKey();
+                    }
                     else if (parseKeywordIf(ctx, "FOREIGN KEY")) {
                         return s1.dropForeignKey(parseIdentifier(ctx));
                     }