Difference between revisions of "SQL Syntax Considerations"
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:* SQL syntax is not case-sensitive, except for table names and field names. | :* SQL syntax is not case-sensitive, except for table names and field names. | ||
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:* If you do a query on different tables that have fields with the same name, you should provide column aliases for those fields. (Otherwise, a query for A.phone and B.phone identifies both sets of values as "phone". | :* If you do a query on different tables that have fields with the same name, you should provide column aliases for those fields. (Otherwise, a query for <tt>A.phone</tt> and <tt>B.phone</tt> identifies both sets of values as "phone". A column alias like <tt>A.phone AS A-phone</tt> makes it possible to tell which table a set of values came from.) | ||
:: ''Learn more:'' [[#column_expr|column_expr]] | :: ''Learn more:'' [[SQL Syntax#column_expr|column_expr]] | ||
Latest revision as of 00:17, 12 December 2012
- Considerations
-
- SQL syntax is not case-sensitive, except for table names and field names.
- Backticks are (`) are needed around any table or field name that is one of the SQL Reserved Words.
- For example: SELECT * FROM `Order`
- Without the backticks, you get an error like this:
- Encountered "Order" at line column 15. Was expecting one of (...
- That error means the parser found a word it recognized, but didn't find other things it expected before it got to that word.
- When either a table name or a field name is reserved word, and both are used together, then backticks are needed around the combination.
- For example: `Order.order_number`
- If you do a query on different tables that have fields with the same name, you should provide column aliases for those fields. (Otherwise, a query for A.phone and B.phone identifies both sets of values as "phone". A column alias like A.phone AS A-phone makes it possible to tell which table a set of values came from.)
- Learn more: column_expr