db_query

Tags: sqlite

Description

This function is used to execute an SQL query on an opened SQLite database.

Name Description
DB:db The database handle to query.
query[] The query to execute.

Returns

The query result index (starting at 1).

Examples

new DB:db_handle;
// ...
public OnGameModeInit()
{
	// Create a connection to the database
	if((db_handle = db_open("example.db")) == DB:0)
	{
		// Error
		print("Failed to open a connection to \"example.db\".");
		SendRconCommand("exit");
	}
	else
	{
		// Success
		// Creates a "player spawn log" table, if it doesn't exists, and frees the result
		db_free_result(db_query(db_handle, "CREATE TABLE IF NOT EXISTS `spawn_log`(`ID` INTEGER PRIMARY KEY AUTOINCREMENT,`PlayerID` INTEGER NOT NULL,`PlayerName` VARCHAR(24) NOT NULL)"));
		print("Successfully created a connection to \"example.db\".");
	}
	// ...
	return 1;
}

public OnGameModeExit()
{
	// If there is a database connection, close it
	if(db_handle) db_close(db_handle);
	// ...
	return 1;
}

public OnPlayerSpawn(playerid)
{
	// Declare "query" and "p_name"
	static query[98], p_name[MAX_PLAYER_NAME+1];

	// Stores the name of the player to "p_name"
	GetPlayerName(playerid, p_name, sizeof p_name);

	// Formats "query"
	format(query, sizeof query, "INSERT INTO `spawn_log` (`PlayerID`,`PlayerName`) VALUES (%d,'%s')", playerid, p_name);

	// Inserts something into "spawn_log" and frees the result
	db_free_result(db_query(db_handle, query));
	// ...
	return 1;
}

// Example function
GetNameBySpawnID(spawn_id)
{
	// Declare "p_name"
	new p_name[MAX_PLAYER_NAME+1];

	// Declare "query" and "db_result"
	static query[60], DBResult:db_result;

	// Formats "query"
	format(query, sizeof query, "SELECT `PlayerName` FROM `spawn_log` WHERE `ID`=%d", spawn_id);

	// Selects the player name by using "spawn_id"
	db_result = db_query(db_handle, query);

	// If there is any valid entry
	if(db_num_rows(db_result))
	{
		// Store data from "PlayerName" into "p_name"
		db_get_field(db_result, 0, p_name, sizeof p_name);
	}

	// Frees the result
	db_free_result(db_result);

	// Returns "p_name"
	return p_name;
}

Notes

WARNING

Always free the result by using db_free_result!

  • db_open: Open a connection to an SQLite database
  • db_close: Close the connection to an SQLite database
  • db_query: Query an SQLite database
  • db_free_result: Free result memory from a db_query
  • db_num_rows: Get the number of rows in a result
  • db_next_row: Move to the next row
  • db_num_fields: Get the number of fields in a result
  • db_field_name: Returns the name of a field at a particular index
  • db_get_field: Get content of field with specified ID from current result row
  • db_get_field_assoc: Get content of field with specified name from current result row
  • db_get_field_int: Get content of field as an integer with specified ID from current result row
  • db_get_field_assoc_int: Get content of field as an integer with specified name from current result row
  • db_get_field_float: Get content of field as a float with specified ID from current result row
  • db_get_field_assoc_float: Get content of field as a float with specified name from current result row
  • db_get_mem_handle: Get memory handle for an SQLite database that was opened with db_open.
  • db_get_result_mem_handle: Get memory handle for an SQLite query that was executed with db_query.
  • db_debug_openfiles
  • db_debug_openresults