- In Oracle , you can enclose the keyword in double quotes only. But because the strings in the double quotation marks in Oracle are case-sensitive, Oracle turns the field names to all uppercase regardless of whether the table is created or the query, so unless the table is created in double quotation marks, the field names are all uppercase, and the SQL statement must be double-quoted at a later query. If not added, Oracle will turn the field name to uppercase to prompt an "invalid identifier." Similarly, query ordinary fields can also be obtained by double quotation marks, but the field names within the double quotation marks must be all uppercase, for example, select "Any_field_name" from TableName
- In SQL Server , you can enclose the keyword in square brackets [] or double quotation marks. Field names are not case-sensitive under any circumstances.
- Enclose the table and column names in MySQL with ' (backticks). Field names are also case insensitive.
What about database column names using keywords?