Optionally allow use of stored procedures for MySql to drop columns in db migration

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/DdlGenerator.java

@@ -50,6 +50,7 @@ public class DdlGenerator implements SpiDdlGenerator {
   private final ScriptTransform scriptTransform;
   private final Platform platform;
   private final String platformName;
+  private final boolean useMigrationStoredProcedures;
 
   private CurrentModel currentModel;
   private String dropAllContent;
@@ -71,9 +72,11 @@ public class DdlGenerator implements SpiDdlGenerator {
       log.warn("DDL can't be run on startup with TenantMode " + config.getTenantMode());
       this.runDdl = false;
       this.ddlAutoCommit = false;
+      this.useMigrationStoredProcedures = false;
     } else {
       this.runDdl = config.isDdlRun();
       this.ddlAutoCommit = databasePlatform.isDdlAutoCommit();
+      this.useMigrationStoredProcedures = config.getDatabasePlatform().isUseMigrationStoredProcedures();
     }
     this.scriptTransform = createScriptTransform(config);
     this.baseDir = initBaseDir();
@@ -187,7 +190,7 @@ public class DdlGenerator implements SpiDdlGenerator {
 
   protected void runDropSql(Connection connection) throws IOException {
     if (!createOnly) {
-      if (extraDdl && jaxbPresent) {
+      if (extraDdl && jaxbPresent && useMigrationStoredProcedures) {
         String extraApply = ExtraDdlXmlReader.buildExtra(platform, true);
         if (extraApply != null) {
           runScript(connection, false, extraApply, "extra-ddl");
@@ -210,7 +213,7 @@ public class DdlGenerator implements SpiDdlGenerator {
     if (extraDdl && jaxbPresent) {
       if (currentModel().isTablePartitioning()) {
         String extraPartitioning = ExtraDdlXmlReader.buildPartitioning(platform);
-        if (extraPartitioning != null && !extraPartitioning.isEmpty()) {
+        if (extraPartitioning != null && !extraPartitioning.isEmpty()  && useMigrationStoredProcedures) {
           runScript(connection, false, extraPartitioning, "builtin-partitioning-ddl");
         }
       }

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/DefaultDbMigration.java

@@ -392,19 +392,25 @@ public class DefaultDbMigration implements DbMigration {
   private void generateExtraDdl(File migrationDir, DatabasePlatform dbPlatform, boolean tablePartitioning) throws IOException {
     if (dbPlatform != null) {
       if (tablePartitioning && includeBuiltInPartitioning) {
-        generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.readBuiltinTablePartitioning());
+        generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.readBuiltinTablePartitioning(), true);
       }
-      generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.readBuiltin());
-      generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.read());
+      generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.readBuiltin(), true);
+      generateExtraDdlFor(migrationDir, dbPlatform, ExtraDdlXmlReader.read(), false);
     }
   }
 
-  private void generateExtraDdlFor(File migrationDir, DatabasePlatform dbPlatform, ExtraDdl extraDdl) throws IOException {
+  private void generateExtraDdlFor(File migrationDir, DatabasePlatform dbPlatform, ExtraDdl extraDdl, boolean isBuiltin) throws IOException {
     if (extraDdl != null) {
       List<DdlScript> ddlScript = extraDdl.getDdlScript();
       for (DdlScript script : ddlScript) {
         if (!script.isDrop() && matchPlatform(dbPlatform.getPlatform(), script.getPlatforms())) {
-          writeExtraDdl(migrationDir, script);
+          if (script.isInit()) {
+            if (!isBuiltin || dbPlatform.isUseMigrationStoredProcedures()) {
+              writeExtraDdl(migrationDir, script);
+            }
+          } else {
+            writeExtraDdl(migrationDir, script);
+          }
         }
       }
     }

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/MySqlDdl.java

@@ -18,12 +18,15 @@ public class MySqlDdl extends PlatformDdl {
   // this flag is for compatibility. Use it with care.
   private static final boolean USE_CHECK_CONSTRAINT = Boolean.getBoolean("ebean.mysql.useCheckConstraint");
 
+  private final boolean useMigrationStoredProcedures;
+
   public MySqlDdl(DatabasePlatform platform) {
     super(platform);
     this.alterColumn = "modify";
     this.dropUniqueConstraint = "drop index";
     this.historyDdl = new MySqlHistoryDdl();
     this.inlineComments = true;
+    this.useMigrationStoredProcedures = platform.isUseMigrationStoredProcedures();
   }
 
   /**
@@ -34,6 +37,15 @@ public class MySqlDdl extends PlatformDdl {
     return "drop index " + maxConstraintName(indexName) + " on " + tableName;
   }
 
+  @Override
+  public void alterTableDropColumn(final DdlBuffer buffer, final String tableName, final String columnName) throws IOException {
+    if (this.useMigrationStoredProcedures) {
+      buffer.append("CALL usp_ebean_drop_column('").append(tableName).append("', '").append(columnName).append("')").endOfStatement();
+    } else {
+      super.alterTableDropColumn(buffer, tableName, columnName);
+    }
+  }
+
   /**
    * Return the drop foreign key clause.
    */