self::assertEquals('CONCAT(column1, column2, column3)',$this->platform->getConcatExpression('column1','column2','column3'),'Concatenation function is not correct');
self::assertEquals('column1 || column2 || column3',$this->platform->getConcatExpression('column1','column2','column3'),'Concatenation expression is not correct');
self::assertEquals('SUBSTRING(column FROM 5)',$this->platform->getSubstringExpression('column',5),'Substring expression without length is not correct');
self::assertEquals('SUBSTRING(column FROM 5)',$this->platform->getSubstringExpression('column',5));
self::assertEquals('SUBSTRING(column FROM 1 FOR 5)',$this->platform->getSubstringExpression('column',1,5),'Substring expression with length is not correct');
self::assertEquals('SUBSTRING(column FROM 1 FOR 5)',$this->platform->getSubstringExpression('column',1,5));
self::assertEquals('(column1 + column2 + column3)',$this->platform->getConcatExpression('column1','column2','column3'),'Concatenation expression is not correct');
self::assertEquals('column1 || column2 || column3',$this->platform->getConcatExpression('column1','column2','column3'),'Concatenation expression is not correct');
self::assertEquals('SUBSTR(column, 5, LENGTH(column))',$this->platform->getSubstringExpression('column',5),'Substring expression without length is not correct');