*** 1,5 **** --- 1,25 ---- FAQ + Q) How atomic are the SQL statements? Are UPDATE/INSERT/SELECT/DELETE atomic(e.g, can you modify multiple cross-dependant rows, under the assumption that no one of them could be read by a SELECT thread from another connection)? What about nested queries? What about triggers? For example: If a trigger renumbers a sequencial integer column on INSERT/DELETE, can it be assumed a SELECT statement from another connection won't be capable of reading a non-sequencial temporary column state between the INSERT/DELETE and the trigger action? + + ------ + + Q) Is there a command to check if a table exists? + + ------ + + Q) Is there a command or a perfered method to rename a table? + + ------ + + Q) Is there an expression for checking if a column exists? + + ------ + + Q) Can CREATE ... (column_def) be combined with CREATE ... AS SELECT..., as in CREATE ... (column_def) AS SELECT...(makes a merged table)? + + ------ + Q) I am using a column named id integer primary key. I also have a url column. Is there a prefered way to check if a url is a duplicate before inserting a new record? ------
Small. Fast. Reliable.
Choose any three.
Choose any three.
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