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db_get_field
warning
This function starts with a lowercase letter.
Description
Get the content of a field from db_query
Name | Description |
---|---|
DBResult:dbresult | The result to get the data from. |
field | The field to get the data from. |
result[] | The result. |
maxlength | The max length of the field. |
Returns
Returns 1 if result set handle is valid and the column is available, otherwise 0.
Example
// examples.inc
// ...
static FindFieldIndexByName(DBResult:dbResultSet, const fieldName[])
{
// Return value variable with default return value
new ret = -1;
// Field count
new field_count = db_num_fields(dbResultSet);
// Current field name
new current_field_name[32];
// Iterate through all fields
for (new field_index; field_index < field_count; field_index++)
{
// Get field name
if (db_field_name(dbResultSet, field_index, current_field_name, sizeof current_field_name))
{
// Compare searched field name to current field name
if (!strcmp(fieldName, current_field_name))
{
// Success, store field index to return value variable
ret = field_index;
// Break out of the loop
break;
}
}
}
// Return found field index or "-1"
return ret;
}
Examples_ListNames(DB:dbConnectionHandle)
{
// Database result set
new DBResult:db_result_set = db_query("SELECT `name` FROM `examples`");
// If database result set is valid
if (db_result_set)
{
// Get target field index
new target_field_index = FindFieldIndexByName(db_result_set, "name");
// Check if field index is valid
if (target_field_index >= 0)
{
// Allocate some memory to store results
new result[256];
// Do operations
do
{
// Add value from "example" field to the return value variable
db_get_field(db_result_set, target_field_index, result, sizeof result);
}
// While next row could be fetched
while (db_next_row(db_result_set));
}
// Free result set
db_free_result(db_result_set);
}
}
// mode.pwn
// ...
#include <examples>
static DB:gDBConnectionHandle;
// ...
public OnGameModeInit()
{
// ...
// Create a connection to a database
gDBConnectionHandle = db_open("example.db");
// If connection to the database exists
if (gDBConnectionHandle)
{
// Successfully created a connection to the database
print("Successfully created a connection to database \"example.db\".");
Examples_ListNames(gDBConnectionHandle);
}
else
{
// Failed to create a connection to the database
print("Failed to open a connection to database \"example.db\".");
}
// ...
return 1;
}
public OnGameModeExit()
{
// Close the connection to the database if connection is open
if (db_close(gDBConnectionHandle))
{
// Extra cleanup
gDBConnectionHandle = DB:0;
}
// ...
return 1;
}
Notes
warning
Using an invalid handle other than zero will crash your server! Get a valid database connection handle by using db_query.
Related Functions
- 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_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: The function gets the number of open database connections for debugging purposes.
- db_debug_openresults: The function gets the number of open database results.