How can I view the contents of a prepared statement?

php mysql mysqli
Stomped picture Stomped · Feb 20, 2010 · Viewed 36.8k times · Source

I'm working on learning to use prepared statements with mysqli in PHP and usually, if I'm having a problem with a query I just echo it to the screen to see what it looks like as a first step.

How can I do that with a prepared statement?

I'd like to see the SQL statement after the variables are substituted.

Answer

Pascal MARTIN picture Pascal MARTIN · Feb 20, 2010

Using prepared statements:

  • When you prepare the statement, it is sent to the MySQL server
  • When you bind the variables + execute the statement, only the variables are sent to the MySQL server
  • And the statement + bound variables are executed on the MySQL server -- without it re-doing the "preparation" each time the statement is executed (which is why prepared statements can be good for performance when the same statement is executed several times)

There is no "building" of an SQL query on the PHP side, so, there is no way to actually get that query.

Which means that if you want to see an SQL query, you have to use, well, SQL queries, and not prepared statements.

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