package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.core.OracleDatabase;

 import liquibase.database.core.PostgresDatabase;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.SetColumnRemarksStatement;

 public class SetColumnRemarksGenerator extends AbstractSqlGenerator<SetColumnRemarksStatement> {

     @Override

     public int getPriority() {

         return PRIORITY_DEFAULT;

     }

     @Override

     public boolean supports(SetColumnRemarksStatement statement, Database database) {

         return database instanceof OracleDatabase || database instanceof PostgresDatabase;

     }

     public ValidationErrors validate(SetColumnRemarksStatement setColumnRemarksStatement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

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

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

         validationErrors.checkRequiredField("remarks", setColumnRemarksStatement.getRemarks());

         return validationErrors;

     }

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

         return new Sql[] { new UnparsedSql("COMMENT ON COLUMN "

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

                 + "."

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

                         statement.getColumnName()) + " IS '" + database.escapeStringForDatabase(statement.getRemarks())

                 + "'") };

     }

 }