如何使用 SQL 查询在列的每一行中添加加号（+）？

Question

I have a database with a column containing phone numbers. I want to add plus(+) sign in the beginning of every phone number.

UPDATE Table 
SET Phone = CONCAT('+', Phone)

This is the query I'm using to insert any other character, but it doesn't seem to work with + sign. It says 0 row(s) affected Rows matched: 4023 Changed: 0 Warnings: 0 , which means nothing has changed.

Even if I do SET Phone = CONCAT('+91', Phone) , only 91 is being inserted and not the plus sign.

Answer 1

I think I understood what's going on here. Your Table is probably using integer data type for Phone column. In this case Phone = CONCAT('+91', Phone) implicitly converts value to character type, adds leading "+" but then converts it back to integer type to store value.

You might want to do something like

ALTER TABLE `Table` MODIFY Phone Varchar(100);

(please choose column type accordingly)

I reproduced it here http://sqlfiddle.com/#!9/5b3a651/1