大约有 9,000 项符合查询结果（耗时：0.0222秒） [XML]
How to remove a column from an existing table?
...n do this by querying system tables or using third party tools such as ApexSQL Search (free) or Red Gate Dependency tracker (premium but more features). There a whole thread on foreign keys here
share
|
...
How do I get SUM function in MySQL to return '0' if no values are found?
Say I have a simple function in MySQL:
4 Answers
4
...
Laravel Eloquent: How to get only certain columns from joined tables
...
I tried this and it shows an error SQLSTATE[42S22]: Column not found and it's SQL doesn't include the table in the with. The sql that it appears on the error is "SELECT fk_table.column1 FROM main_table".
– Michel Ayres
A...
LINQ To Entities does not recognize the method Last. Really?
...n comes down to the fact that eventually it has to translate that query to SQL and SQL has a SELECT TOP (in T-SQL) but not a SELECT BOTTOM (no such thing).
There is an easy way around it though, just order descending and then do a First(), which is what you did.
EDIT:
Other providers will possibly...
How do write IF ELSE statement in a MySQL query
How do I write an IF ELSE statement in a MySQL query?
5 Answers
5
...
What's the difference between using INDEX vs KEY in MySQL?
...
When looking at table info in the latest version of SQLYog it shows KEY keyname (column_name) when I created the table with INDEX keyname (column_name). The fact that it is a synonym explains it perfectly.
– crmpicco
Apr 2 '14 at 10:10
...
What is cardinality in MySQL?
What is cardinality in MySQL? Please explain in simple, non-technical language.
8 Answers
...
Database, Table and Column Naming Conventions? [closed]
...
I recommend checking out Microsoft's SQL Server sample databases:
https://github.com/Microsoft/sql-server-samples/releases/tag/adventureworks
The AdventureWorks sample uses a very clear and consistent naming convention that uses schema names for the organizatio...
Checking if a field contains a string
...
https://docs.mongodb.com/manual/reference/sql-comparison/
http://php.net/manual/en/mongo.sqltomongo.php
MySQL
SELECT * FROM users WHERE username LIKE "%Son%"
MongoDB
db.users.find({username:/Son/})
...
LINQ - Left Join, Group By, and Count
Let's say I have this SQL:
5 Answers
5
...