Question

I have problems with sqlite3 and “num_rows”. I cannot ask for num_rows of a result like mysql.Now i wan’t to automate my SELECT query to ask for the rowcount.
Is there a way to replace all between two patterns?

Like

    SELECT date,name,etc FROM myTable WHERE gender=1
// to
SELECT count(*) FROM myTable WHERE gender=1

I must replace all between SELECT and FROM with count(*).
Can i do this this preg_replace?

Answer 1

For your example provided it’s simple, but I guess it won’t work for all query syntaxes. But have it a try:

PHP code (don’t know language you do use):

$count_sql = preg_replace('/^(SELECT)\\s+.*?\\s+(FROM.*)$/s', '$1 count(*) $2', $select_sql);

But I guess, there is a more elegant way to find the num_rows thing. You could use a subquery, like:

SELECT COUNT(*) FROM ( *** original query here *** )

It’s not very efficient, but you don’t have to deal with the query syntax.