You can register a reporter to monitor all errors.

 [WCTStatistics SetGlobalErrorReport:^(WCTError* error) {
    NSLog(@"%@", error);
 }];

You can register a tracer to monitor the performance of all SQLs. It returns 1. The collection of SQLs and the executions count of each SQL. 2. Time consuming in nanoseconds. 3. Tag of database. Note that: 1. You should register trace before all db operations. 2. Global tracer will be recovered by db tracer.

[WCTStatistics SetGlobalPerformanceTrace:^(WCTTag tag, NSDictionary<NSString*, NSNumber*>* sqls, NSInteger cost) {
    NSLog(@"Tag: %d", tag);
    [sqls enumerateKeysAndObjectsUsingBlock:^(NSString *sql, NSNumber *count, BOOL *) {
        NSLog(@"SQL: %@ Count: %d", sql, count.intValue);
    }];
    NSLog(@"Total cost %ld nanoseconds", (long)cost);
}];

You can register a tracer to monitor the execution of all SQLs. It returns a prepared or executed SQL. Note that you should register trace before all db operations.

[WCTStatistics SetGlobalSQLTrace:^(NSString* sql) {
    NSLog(@"SQL: %@", sql);
}];

[WCTStatistics SetGlobalPerformanceTrace:]