package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.typeconversion.TypeConverterFactory;

 import liquibase.database.core.DerbyDatabase;

 import liquibase.database.core.HsqlDatabase;

 import liquibase.database.core.MSSQLDatabase;

 import liquibase.database.core.H2Database;

 import liquibase.database.structure.Column;

 import liquibase.database.structure.Table;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.AddAutoIncrementStatement;

 public class AddAutoIncrementGenerator extends AbstractSqlGenerator<AddAutoIncrementStatement> {

     @Override

     public int getPriority() {

         return PRIORITY_DEFAULT;

     }

     @Override

     public boolean supports(AddAutoIncrementStatement statement, Database database) {

         return (database.supportsAutoIncrement() && !(database instanceof DerbyDatabase)

                 && !(database instanceof MSSQLDatabase) && !(database instanceof HsqlDatabase) && !(database instanceof H2Database));

     }

     public ValidationErrors validate(AddAutoIncrementStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

         validationErrors.checkRequiredField("columnName", statement.getColumnName());

         validationErrors.checkRequiredField("tableName", statement.getTableName());

         return validationErrors;

     }

     public Sql[] generateSql(AddAutoIncrementStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {

         String sql = "ALTER TABLE "

                 + database.escapeTableName(statement.getSchemaName(), statement.getTableName())

                 + " MODIFY "

                 + database.escapeColumnName(statement.getSchemaName(), statement.getTableName(),

                         statement.getColumnName())

                 + " "

                 + TypeConverterFactory.getInstance().findTypeConverter(database)

                         .getDataType(statement.getColumnDataType(), true) + " AUTO_INCREMENT";

         return new Sql[] { new UnparsedSql(sql, new Column().setTable(

                 new Table(statement.getTableName()).setSchema(statement.getSchemaName())).setName(

                 statement.getColumnName())) };

     }

 }