How to use the SQL key word EXISTS? - 未名空间MITBBS历史存档

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How to use the SQL key word EXISTS?

How to use the SQL key word EXISTS?# Database - 数据库

m*f2002-03-19 08:03

1 楼

I use mysql for a web application.
This application requires the customer to log in using his email address and a
password.
Now when I get the customer password, I want to check the customer table in my
database and see if that e-mail address exists. If it exists, I then check if
the password the customer has just entered matches the one in the customer
table associated with the e-mail address.
What SQL statement should I use to check if the customer-supplied e-mail
address exists in the custom

x*u2002-03-19 08:03

2 楼

画蛇添足啊。
SELECT customer_password FROM customer WHERE customer_email = 'bill...';
or more simply
SELECT customer_password FROM customer WHERE customer_email = 'bill...'
AND customer_password = '...';

a
my
if

【在 m****f 的大作中提到】

: I use mysql for a web application.
: This application requires the customer to log in using his email address and a
: password.
: Now when I get the customer password, I want to check the customer table in my
: database and see if that e-mail address exists. If it exists, I then check if
: the password the customer has just entered matches the one in the customer
: table associated with the e-mail address.
: What SQL statement should I use to check if the customer-supplied e-mail
: address exists in the custom