package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.typeconversion.TypeConverterFactory;

 import liquibase.database.core.SQLiteDatabase;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.DeleteStatement;

 import java.util.Date;

 public class DeleteGenerator extends AbstractSqlGenerator<DeleteStatement> {

     @Override

     public boolean supports(DeleteStatement statement, Database database) {

         return !(database instanceof SQLiteDatabase);

     }

     public ValidationErrors validate(DeleteStatement deleteStatement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

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

         return validationErrors;

     }

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

         StringBuffer sql = new StringBuffer("DELETE FROM "

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

         if (statement.getWhereClause() != null) {

             String fixedWhereClause = " WHERE " + statement.getWhereClause();

             for (Object param : statement.getWhereParameters()) {

                 fixedWhereClause = fixedWhereClause.replaceFirst("\\?", convertToString(param, database));

             }

             sql.append(" ").append(fixedWhereClause);

         }

         return new Sql[] { new UnparsedSql(sql.toString()) };

     }

     private String convertToString(Object newValue, Database database) {

         String sqlString;

         if (newValue == null) {

             sqlString = "NULL";

         } else if (newValue instanceof String && database.shouldQuoteValue(((String) newValue))) {

             sqlString = "'" + newValue + "'";

         } else if (newValue instanceof Date) {

             sqlString = database.getDateLiteral(((Date) newValue));

         } else if (newValue instanceof Boolean) {

             if (((Boolean) newValue)) {

                 sqlString = TypeConverterFactory.getInstance().findTypeConverter(database).getBooleanType()

                         .getTrueBooleanValue();

             } else {

                 sqlString = TypeConverterFactory.getInstance().findTypeConverter(database).getBooleanType()

                         .getFalseBooleanValue();

             }

         } else {

             sqlString = newValue.toString();

         }

         return sqlString;

     }

 }