detect mysql errors without executing it

Question

Suppose I make a query \"UPDATE table SET etc etc\"

Then I \"Execute\" this query

if the query is fine, it executes and if the query has errors,

Answer 1

EXPLAIN does the trick if you're running MySQL 5.6 or greater.

explain update whatever;

If the query is ok, it shows the execution plan. Else, it returns the syntax error.

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If you're running a lesser version of MySQL, I see a few options:

1. The recommended option: Have a test database ready that mirrors your production database at least in structure. Ideally have it populated with test data to verify the query is not only syntactically correct; but that it works as expected.
2. Run the query in the scope of a TRANSACTION that is immediately rolled back.
3. Run a version of the query that is slightly modified to match NO ROWS.

For instance:

update table set col1 = @val1 where col2 = @val2;

Becomes:

update table set col1 = @val1 where (col2 = @val2) and 1=0;

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So, if you're running 5.6 or greater, the EXPLAIN trick is neat. If not, options 2 and 3 from list are also neat(ish) tricks. But, you should generally be hitting a development server with your in-development queries anyway.