SQLite.au3 - how to test if table exsists already.

[John117]

I have a simple test script for this post.

Trying to get my script to verify if a table exsists, if not, then add the table.

Have tried sqlite statements I have found. none seem to work for me. Anyone here know sqlite enough to make this check if the table exsists before adding it. Just looking to get rid of the error the second time it is run.

It runs in my main script everytime the script loads. -needs to.

#include <SQLite.au3>
#include <SQLite.dll.au3>

_Query_Database_Startup_Info()

Func _Query_Database_Startup_Info()
 Global $SqlLiteDll = _SQLite_Startup()
 If @error Then
  MsgBox(16, "Error", "Failed to start up SQLite, @error = " & @error)
 Else
  $hDB = _SQLite_Open(@ScriptDir & "\CIF1.db")
  If $hDB = 0 Or @error Then
   MsgBox(16, "Error", "Error opening database, @error = " & @error & ", @extended = " & @extended)
  Else
   $sExec = "CREATE TABLE TableNameHere (ID_Here INTEGER PRIMARY KEY,a,b,c,d,e);"
   _SQLite_Exec($hDB, $sExec)
   _SQLite_Close($hDB)
   _SQLite_Shutdown()
  EndIf
 EndIf
EndFunc   ;==>_Query_Database_Startup_Info

[kylomas]

john117,

See this thread

kylomas

[jchd]

select count(*) from sqlite_master where type='table' and name like 'mytable'

will return 0 or 1 depending on table existence.

Now the kludge above is probably not what you actually need. Try this instead:

$sExec = "CREATE TABLE if not exists TableNameHere (ID_Here INTEGER PRIMARY KEY,a,b,c,d,e);"

Pure SQL does it. See SQLite docs.

[kylomas]

jchd,

Yes, that is the solution in the thread I cited. Am I mistaken?

kylomas

[John117]

Very useful stuff from both of you! Thank you, will use for much more than the question stated.

$sExec = "CREATE TABLE if not exists TableNameHere (ID_Here INTEGER PRIMARY KEY,a,b,c,d,e);"

was very useful!

[jchd]

Pretty standard way to [re]create tables in SQL without having to worry about what happened just before.

BTW, try avoiding declaring columns without a type, even given that SQLite is quite permissive about datatypes. Or rather declare intended types _because_ SQLite is quite smart by its own and will do its best to fulfill your desires.

[John117]

Ok, can you give me an example by rewriting this line?

$sExec = "CREATE TABLE if not exists TableNameHere (ID_Here INTEGER PRIMARY KEY,a,b,c,d,e);"

What would be the positive outcome, or what would it avoid?