package liquibase.sqlgenerator.core;

 import liquibase.changelog.ChangeSet;

 import liquibase.changelog.RanChangeSet;

 import liquibase.database.Database;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.sqlgenerator.SqlGeneratorFactory;

 import liquibase.statement.SqlStatement;

 import liquibase.statement.core.UpdateChangeSetChecksumStatement;

 import liquibase.statement.core.UpdateStatement;

 public class UpdateChangeSetChecksumGenerator extends AbstractSqlGenerator<UpdateChangeSetChecksumStatement> {

     public ValidationErrors validate(UpdateChangeSetChecksumStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

         validationErrors.checkRequiredField("changeSet", statement.getChangeSet());

         return validationErrors;

     }

     public Sql[] generateSql(UpdateChangeSetChecksumStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ChangeSet changeSet = statement.getChangeSet();

         SqlStatement runStatement = null;

         runStatement = new UpdateStatement(database.getLiquibaseSchemaName(), database.getDatabaseChangeLogTableName())

                 .addNewColumnValue("MD5SUM", changeSet.generateCheckSum().toString())

                 .setWhereClause("ID=? AND AUTHOR=? AND FILENAME=?")

                 .addWhereParameters(changeSet.getId(), changeSet.getAuthor(), changeSet.getFilePath());

         return SqlGeneratorFactory.getInstance().generateSql(runStatement, database);

     }

 }