大约有 44,000 项符合查询结果（耗时：0.0115秒） [XML]
How to prepend a string to a column value in MySQL?
...
You can use the CONCAT function to do that:
UPDATE tbl SET col=CONCAT('test',col);
If you want to get cleverer and only update columns which don't already have test prepended, try
UPDATE tbl SET col=CONCAT('test',col)
WHERE col NOT LIKE ...
Postgresql GROUP_CONCAT equivalent?
I have a table and I'd like to pull one row per id with field values concatenated.
7 Answers
...
Is it possible to GROUP BY multiple columns using MySQL?
...ly this) group by two columns at same time, I just saw this point:
SELECT CONCAT (col1, '_', col2) AS Group1 ... GROUP BY Group1
share
|
improve this answer
|
follow
...
.NET List Concat vs AddRange
What is the difference between the AddRange and Concat functions on a generic List? Is one recommended over the other?
...
MySQL select with CONCAT condition
... query itself.
You can either repeat the expression:
SELECT neededfield, CONCAT(firstname, ' ', lastname) as firstlast
FROM users
WHERE CONCAT(firstname, ' ', lastname) = "Bob Michael Jones"
or wrap the query
SELECT * FROM (
SELECT neededfield, CONCAT(firstname, ' ', lastname) as firstlast
...
Javascript Array Concat not working. Why?
...
The concat method doesn't change the original array, you need to reassign it.
if ( ref instanceof Array )
this.refs = this.refs.concat( ref );
else
this.refs.push( ref );
...
How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)
...
concat.js is being included in the concat task's source files public/js/*.js. You could have a task that removes concat.js (if the file exists) before concatenating again, pass an array to explicitly define which files you wa...
String concatenation in MySQL
I am using MySQL and MySQL Workbench 5.2 CE. When I try to concatenate 2 columns, last_name and first_name , it doesn't work :
...
Update MongoDB field using value of another field
...lection.<update method>(
{},
[
{"$set": {"name": { "$concat": ["$firstName", " ", "$lastName"]}}}
]
)
MongoDB 3.4+
In 3.4+ you can use $addFields and the $out aggregation pipeline operators.
db.collection.aggregate(
[
{ "$addFields": {
"name": {...
Include headers when using SELECT INTO OUTFILE?
... how to get column list of table my_table in my_schema.
-- override GROUP_CONCAT limit of 1024 characters to avoid a truncated result
set session group_concat_max_len = 1000000;
select GROUP_CONCAT(CONCAT("'",COLUMN_NAME,"'"))
from INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'my_table'
AND TABLE...