package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.core.MSSQLDatabase;

 import liquibase.database.core.SybaseASADatabase;

 import liquibase.database.core.SybaseDatabase;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.AddUniqueConstraintStatement;

 public class AddUniqueConstraintGeneratorTDS extends AddUniqueConstraintGenerator {

     public AddUniqueConstraintGeneratorTDS() {

     }

     @Override

     public int getPriority() {

         return PRIORITY_DATABASE;

     }

     @Override

     public boolean supports(AddUniqueConstraintStatement statement, Database database) {

         return (database instanceof MSSQLDatabase) || (database instanceof SybaseDatabase)

                 || (database instanceof SybaseASADatabase);

     }

     @Override

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

             SqlGeneratorChain sqlGeneratorChain) {

         final String sqlTemplate = "ALTER TABLE %s ADD CONSTRAINT %s UNIQUE (%s)";

         final String sqlNoContraintNameTemplate = "ALTER TABLE %s ADD UNIQUE (%s)";

         if (statement.getConstraintName() == null) {

             return new Sql[] { new UnparsedSql(String.format(sqlNoContraintNameTemplate,

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

                     database.escapeColumnNameList(statement.getColumnNames()))) };

         } else {

             return new Sql[] { new UnparsedSql(String.format(sqlTemplate,

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

                     database.escapeConstraintName(statement.getConstraintName()),

                     database.escapeColumnNameList(statement.getColumnNames()))) };

         }

     }

 }