DbPoll: Difference between revisions
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===Returns=== | ===Returns=== | ||
*''nil:'' Returns nil if the query results are not yet ready. You should try again in a little while. (If you give up waiting for a result, be sure to call [[dbFree]]) | *''nil:'' Returns nil if the query results are not yet ready. You should try again in a little while. (If you give up waiting for a result, be sure to call [[dbFree]]) | ||
*''false | *''false'' Returns false if the query string contained an error, the connection has been lost or the query handle is incorrect. This automatically frees the query handle, so you do not have to call [[dbFree]]. | ||
** This also returns two extra values: error code and error message. See the example on how to retrieve them, | |||
*''table:'' Returns a table when the results are ready. This automatically frees the query handle, so you do not have to call [[dbFree]]. | *''table:'' Returns a table when the results are ready. This automatically frees the query handle, so you do not have to call [[dbFree]]. | ||
** This also returns an extra value: number of affected rows | |||
==Example== | ==Example== | ||
This example waits until a result is ready | This example waits until a result is ready: | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
local result = dbPoll ( qh, -1 ) | local result = dbPoll ( qh, -1 ) | ||
</syntaxhighlight> | |||
This example shows the possible return values: | |||
<syntaxhighlight lang="lua"> | |||
local result, numrows, errmsg = dbPoll ( qh, -1 ) | |||
if result == nil then | |||
outputConsole( "dbPoll result not ready yet" ) | |||
elseif result == false then | |||
outputConsole( "dbPoll failed. Error code: " .. tostring(numrows) .. " Error message: " .. tostring(errmsg) ) | |||
else | |||
outputConsole( "dbPoll succeeded. Number of affected rows: " .. tostring(numrows) ) | |||
end | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Revision as of 00:51, 29 October 2011
Available only in MTA SA 1.1.1 r3328 and onwards This function checks the progress of a database query.
Syntax
table dbPoll ( handle queryHandle, int timeout )
Required Arguments
- queryHandle: A query handle previously returned from dbQuery
- timeout: How many milliseconds to wait for a result. Use 0 for and instant response (which may return nil). Use -1 to wait until a result is ready. Note: A wait here will freeze the entire server just like the executeSQL* functions
Returns
- nil: Returns nil if the query results are not yet ready. You should try again in a little while. (If you give up waiting for a result, be sure to call dbFree)
- false Returns false if the query string contained an error, the connection has been lost or the query handle is incorrect. This automatically frees the query handle, so you do not have to call dbFree.
- This also returns two extra values: error code and error message. See the example on how to retrieve them,
- table: Returns a table when the results are ready. This automatically frees the query handle, so you do not have to call dbFree.
- This also returns an extra value: number of affected rows
Example
This example waits until a result is ready:
local result = dbPoll ( qh, -1 )
This example shows the possible return values:
local result, numrows, errmsg = dbPoll ( qh, -1 )
if result == nil then
outputConsole( "dbPoll result not ready yet" )
elseif result == false then
outputConsole( "dbPoll failed. Error code: " .. tostring(numrows) .. " Error message: " .. tostring(errmsg) )
else
outputConsole( "dbPoll succeeded. Number of affected rows: " .. tostring(numrows) )
end
Requirements
This template will be deleted.
See Also