updating the mysql table if query store_num exits - php

Question

Everyone!
I am working on application using php and mysql. Basically, initially, I am inserting the new data entries using html form into the database where store# is my primary key. For now I can not update the existing store# (as its my primary key) and get a message saying "Duplicate entry for store 967 (example)".
I want to update the "store" table if entery exists. Here is my code posted below, but I am getting another error message
Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '['967'],address=['500 kipling avenue 1'],dsm_name=['n/a'],phone=['416-967-' at line 1
I am not sure if I am using the if conditional at right spot.
**$sql = "INSERT INTO `stores`(`store_num`, `address`, `dsm_name`, `phone`, `router_type`, `high_speed_pri`, `dsl_log`, `dsl_pass`, `secondary_conn`, `sec_dsl`, `sec_pass`) VALUES ('$store' , '$address', '$dsm', '$phone', '$router', '$highspeedpr', '$dsllog', '$dslpas', '$secondary_conn' , '$secdsl' , '$sec_pass')";
$mysqli_query = "SELECT * from 'stores' WHERE $store = 'store_num'";
if ($mysqli_query == TRUE){
$sql = "UPDATE `stores` SET `store_num`=['$store'],`address`=['$address'],`dsm_name`=['$dsm'],`phone`=['$phone'],`router_type`=['$router'],`high_speed_pri`=['$highspeedpr'],`dsl_log`=['$dsllog'],`dsl_pass`=['$dslpas'],`secondary_conn`=['$secondary_conn'],`sec_dsl`=['$secdsl'],`sec_pass`=['$sec_pass'] WHERE 1";
}
if (!mysqli_query($con,$sql)) {
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
?>**

Answer 1

Replace instead of Insert
Since your update statement includes all the same fields as Insert, you can simply use a REPLACE Statement. As stated on the linked documentation:
REPLACE works exactly like INSERT, except that if an old row in the
table has the same value as a new row for a PRIMARY KEY or a UNIQUE
index, the old row is deleted before the new row is inserted. See
Section 13.2.5, “INSERT Syntax”.
So, changing the code to the following should work:
$sql = "REPLACE INTO `stores`(`store_num`, `address`, `dsm_name`, `phone`, `router_type`, `high_speed_pri`, `dsl_log`, `dsl_pass`, `secondary_conn`, `sec_dsl`, `sec_pass`) VALUES ('$store' , '$address', '$dsm', '$phone', '$router', '$highspeedpr', '$dsllog', '$dslpas', '$secondary_conn' , '$secdsl' , '$sec_pass')";
Error Reason
Your problem is with the syntax in the update statement. What is store_num, is it a number or a string?
You should change your syntax to not include the square brackets in the actual mysql query.
If $Store is Number:
=['$store'], to =$store
If $Store is Text:
=['$store'], to ='$store'
Final Recommendation
Even better though will be use prepared statements which are also secure and avoid against SQL injection attacks.

Answer 2

You can do this logic with a single query, using on duplicate key update. First, you have to define store_num as a unique key, if it is not already a unique or primary key:
CREATE UNIQUE INDEX idx_stored_storenum on stores(store_num);
Then use this insert:
INSERT INTO `stores`(`store_num`, `address`, `dsm_name`, `phone`, `router_type`, `high_speed_pri`,
`dsl_log`, `dsl_pass`, `secondary_conn`, `sec_dsl`, `sec_pass`
)
VALUES ('$store' , '$address', '$dsm', '$phone', '$router', '$highspeedpr',
'$dsllog', '$dslpas', '$secondary_conn' , '$secdsl' , '$sec_pass')
ON DUPLICATE KEY UPDATE address = values (address),
dsm_name = values(dsm_name),
. . .
sec_pass = values(sec_pass);
Your particular problem is the square braces, which MySQL doesn't recognize.