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SQL Server: Maximum character length of object names
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Yes, it is 128, except for temp tables, whose names can only be up to 116 character long.
It is perfectly explained here.
And the verification can be easily made with the following script contained in the blog post before:
DECLARE @i NVARCHAR(800)
SELECT ...
What is the best collation to use for MySQL with PHP? [closed]
...names are involved. Depending on the implementation that uses the database tables, this problem could allow malicious users to create a username matching an administrator account.
This problem exposes itself at the very least in early 5.x versions - I'm not sure if this behaviour as changed later.
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Update multiple rows in same query using PostgreSQL
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You can also use update ... from syntax and use a mapping table. If you want to update more than one column, it's much more generalizable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
where c.column_b = t.c...
Using DISTINCT and COUNT together in a MySQL Query
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use
SELECT COUNT(DISTINCT productId) from table_name WHERE keyword='$keyword'
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Could not find stored procedure 'dbo.aspnet_CheckSchemaVersion'
...here to run above command then you can simply run 'aspnet_regsql.exe' executable file.
In order to locate this file open your RUN Command Box by pressing Windows Key + r and put below command in that %windir%\Microsoft.NET\Framework\v4.0.30319 and Hit enter then find 'aspnet_regsql.exe' file. It wi...
Sequelize.js: how to use migrations and sync
...h and the database structure is going to change -- new columns in existing tables as well as new tables, and new associations to existing and new models.
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Downloading MySQL dump from command line
...mp -u [uname] -p --all-databases > all_db_backup.sql
If it's specific tables within a DB, then:
$ mysqldump -u [uname] -p db_name table1 table2 > table_backup.sql
You can even go as far as auto-compressing the output using gzip (if your DB is very big):
$ mysqldump -u [uname] -p db...
How do I (or can I) SELECT DISTINCT on multiple columns?
I need to retrieve all rows from a table where 2 columns combined are all different. So I want all the sales that do not have any other sales that happened on the same day for the same price. The sales that are unique based on day and price will get updated to an active status.
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#1071 - Specified key was too long; max key length is 1000 bytes
... was too long; max key length is 3072 bytes' when ran this script:
CREATE TABLE IF NOT EXISTS test_table1 (
column1 varchar(500) NOT NULL,
column2 varchar(500) NOT NULL,
column3 varchar(500) NOT NULL,
column4 varchar(500) NOT NULL,
column5 varchar(500) NOT NULL,
column6 varchar(500) NOT...
MongoDB/NoSQL: Keeping Document Change History
...ific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of a log) or have a separate h...