diff options
Diffstat (limited to 'sql/udf_example.c')
| -rw-r--r-- | sql/udf_example.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/sql/udf_example.c b/sql/udf_example.c index 26afa538e88..e4757de880d 100644 --- a/sql/udf_example.c +++ b/sql/udf_example.c @@ -173,6 +173,13 @@ void avgcost_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error void avgcost_clear( UDF_INIT* initid, char* is_null, char *error ); void avgcost_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); double avgcost( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); +my_bool avg2_init( UDF_INIT* initid, UDF_ARGS* args, char* message ); +void avg2_deinit( UDF_INIT* initid ); +void avg2_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); +void avg2_clear( UDF_INIT* initid, char* is_null, char *error ); +void avg2_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); +void avg2_remove( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); +double avg2( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error ); my_bool is_const_init(UDF_INIT *initid, UDF_ARGS *args, char *message); char *is_const(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error); @@ -1049,6 +1056,138 @@ avgcost( UDF_INIT* initid, UDF_ARGS* args __attribute__((unused)), return data->totalprice/(double)data->totalquantity; } + +/* +** Average 2 (number, sum)*/ +struct avg2_data +{ + ulonglong count; + double sum; +}; + + +my_bool +avg2_init( UDF_INIT* initid, UDF_ARGS* args, char* message ) +{ + struct avg2_data* data; + + if (args->arg_count != 2) + { + strcpy( + message, + "wrong number of arguments: AVG2() requires two arguments" + ); + return 1; + } + + if ((args->arg_type[0] != INT_RESULT) || (args->arg_type[1] != REAL_RESULT) ) + { + strcpy( + message, + "wrong argument type: AVG2() requires an INT and a REAL" + ); + return 1; + } + + /* + ** force arguments to double. + */ + /*args->arg_type[0] = REAL_RESULT; + args->arg_type[1] = REAL_RESULT;*/ + + initid->maybe_null = 0; /* The result may be null */ + initid->decimals = 4; /* We want 4 decimals in the result */ + initid->max_length = 20; /* 6 digits + . + 10 decimals */ + + if (!(data = (struct avg2_data*) malloc(sizeof(struct avg2_data)))) + { + strmov(message,"Couldn't allocate memory"); + return 1; + } + data->count = 0; + data->sum = 0.0; + + initid->ptr = (char*)data; + + return 0; +} + +void +avg2_deinit( UDF_INIT* initid ) +{ + free(initid->ptr); +} + + +/* This is only for MySQL 4.0 compability */ +void +avg2_reset(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* message) +{ + avgcost_clear(initid, is_null, message); + avgcost_add(initid, args, is_null, message); +} + +/* This is needed to get things to work in MySQL 4.1.1 and above */ + +void +avg2_clear(UDF_INIT* initid, char* is_null __attribute__((unused)), + char* message __attribute__((unused))) +{ + struct avg2_data* data = (struct avg2_data*)initid->ptr; + data->sum= 0.0; + data->count= 0; +} + + +void +avg2_add(UDF_INIT* initid, UDF_ARGS* args, + char* is_null __attribute__((unused)), + char* message __attribute__((unused))) +{ + if (args->args[0] && args->args[1]) + { + struct avg2_data* data = (struct avg2_data*)initid->ptr; + longlong quantity = *((longlong*)args->args[0]); + double sum = *((double*)args->args[1]); + + data->count += quantity; + data->sum += sum; + } +} + + +void +avg2_remove(UDF_INIT* initid, UDF_ARGS* args, + char* is_null __attribute__((unused)), + char* message __attribute__((unused))) +{ + if (args->args[0] && args->args[1]) + { + struct avg2_data* data = (struct avg2_data*)initid->ptr; + longlong quantity = *((longlong*)args->args[0]); + double sum = *((double*)args->args[1]); + + data->count -= quantity; + data->sum -= sum; + } +} + + +double +avg2( UDF_INIT* initid, UDF_ARGS* args __attribute__((unused)), + char* is_null, char* error __attribute__((unused))) +{ + struct avg2_data* data = (struct avg2_data*)initid->ptr; + if (!data->count) + { + *is_null = 1; + return 0.0; + } + + *is_null = 0; + return data->sum/(double)data->count; +} + my_bool myfunc_argument_name_init(UDF_INIT *initid, UDF_ARGS *args, char *message); char *myfunc_argument_name(UDF_INIT *initid, UDF_ARGS *args, char *result, |