I use SQLiteStudio, and the software refuses to take the text function "Left" from me. (by take I assume you mean that you get an error if you try to use the fuction, and the error is "function does not exists" -- if you "take" has some other meaning, please clarify).

This is the forum for the SQLite.

SQLiteStudio is a different application, writen by someone else, supported somewhere else, over which the prople here have no control.

If you have problems with that application you should take it up with the author of that application.

I did not find, except error, information on this function in the documentation

I am surprised you found anything at all since there is no such SQL function in SQLite. SQLiteStudio is an entirely different creature. Perhaps it has a Left function -- you would need to check its documentation.

Is SQLite or SQLiteStudio which does not use this function.

Yes.

The documented function for obtining a substr in SQLite is with the SUBSTR function. It takes the arguments source, start, stop.

The Left 4 characters of the string 'dizzybot' can be found by substr('dizzybot, 1, 4) which will return 'dizz'.

If you want a function called LEFT(data,len) then you can write one or translate to substr(data,1,len),

It takes the arguments source, start, stop width or length.

Merci d'avoir pris le temps de me répondre

Cordialement