mysql,c , Loop through database table and compare user input
Loop through database table and compare user input
Question:
Tag: mysql,c
I am trying to loop through the rows in a MySql table and compare the data in a certain column to some user input using C. Currently my code looks like this:
MYSQL *cxn = mysql_init(NULL);
MYSQL_RES *result;
unsigned int num_fields;
unsigned int num_rows;
char *query_string;
MYSQL_ROW *row;
if (mysql_real_connect(cxn, <em>/*blah blah blah**/</em>) == NULL) {
printf("Please restart the service.");
}
result = mysql_store_result(cxn);
num_rows = mysql_num_rows(result);
num_fields = mysql_num_fields(result);
while (row = mysql_fetch_row(result)) {
for (i = 0; i < num_fields; i++) {
//Confusion occurring here
//if (field[i] @ currentRow == "User input")
// printf("Win");
}
}
Answer:
If you are only looking for fields that match the input, you'll want to search the database using the input string. In other words, write your query string so that it only gives you results that match the user input. This will be much faster than searching through every returned row for your user input.
SELECT * FROM table WHERE Cars=input
If you do need every row to be returned, then you would want your code to read something like this
while (row = mysql_fetch_row(result)) {
for (i = 0; i < num_fields; i++) {
//Confusion occurring here
//if (row[i] == "User input") You can't compare strings in C with ==
if(strcmp(row[i], user_input) == 0))
printf("Win");
}
}
If your user input is a string, however, you'll want to compare using strcmp.
if(strcmp(row[i], user_input) == 0))
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