Question

i have a usertable which includes a field named zip (postal code)
I also have a geo table with latitude, longitude values, based upon zipcodes.

so:

usertable 
table_1 contains fields: zip, latitude,longitude (in last 2 fields all values are NULL)
geotable:
table_2 contains fields: zip, latitude,longitude

The zipcode in table_1 has this format: 1111 AA (4 numbers, 2 letters, usually split by empty character)

The zipcode in table_2 has format: 1111 (only four numbers)

I am trying to find out how an update query should look like?

I want to update the usertable with the values from the geotable, so a search query can be done without any joins. Search queries are the most used queries on this site, The updates/checks seldom.

Thanks in advance for any help!

Answer 1

You could write

UPDATE table_1 SET
  latitude = (SELECT latitude FROM table_2 WHERE table_1.zip LIKE CONCAT(table_2.zip, '%')),
  longitude = (SELECT longitude FROM table_2 WHERE table_1.zip LIKE CONCAT(table_2.zip, '%'));

Unfortunately I don’t believe there is syntax quite similar to what Colin is suggesting. You may find it more efficient to simply select the values from table_2 first and then insert them.