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How do I execute inserts and updates in an Alembic upgrade script?
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This answer assumes you are using declarative (as opposed to class-Mapper-Table or core) to define your models. It should be relatively straightforward to adapt this to the other forms.
Note that Alembic provides some basic data functions: op.bulk_insert() and op.execute(). If the operations are ...
What is Normalisation (or Normalization)?
...he other, which is data corruption. The problem is solved by splitting the table in two, and creating a primary key/foreign key relationship:
UserId(FK) | Car UserId(PK) | UserName
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1 | Toyota 1 | John
2 ...
How to speed up insertion performance in PostgreSQL
I am testing Postgres insertion performance. I have a table with one column with number as its data type. There is an index on it as well. I filled the database up using this query:
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Is a DIV inside a TD a bad idea?
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Using a div instide a td is not worse than any other way of using tables for layout. (Some people never use tables for layout though, and I happen to be one of them.)
If you use a div in a td you will however get in a situation where it might be hard to predict how the elements will be siz...
Oracle find a constraint
...stem generated constraint name. For instance, if we specify NOT NULL in a table declaration. Or indeed a primary or unique key. For example:
SQL> create table t23 (id number not null primary key)
2 /
Table created.
SQL> select constraint_name, constraint_type
2 from user_constraint...
MySQL 启动报错 Table \'mysql.plugin\' doesn\'t exist - 数据库(内核) -...
MySQL 启动报错 Table 'mysql.plugin' doesn't exist 启动报错: opt szy bin mysqld: Table 'mysql.plugin ' doesn 't exist141211 15:06:12 [ERROR] Can 't open t...启动报错:
/opt/szy/bin/mysqld: Table \'mysql.plugin\' doesn\'t exist
141211 15:06:12 [ERROR] Can\'t open the mysql.plug...
Escape single quote character for use in an SQLite query
I wrote the database schema (only one table so far), and the INSERT statements for that table in one file. Then I created the database as follows:
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Split function equivalent in T-SQL?
...to split '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15...' (comma delimited) into a table or table variable.
15 Answers
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SQL Server reports 'Invalid column name', but the column is present and the query works through mana
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I suspect that you have two tables with the same name. One is owned by the schema 'dbo' (dbo.PerfDiag), and the other is owned by the default schema of the account used to connect to SQL Server (something like userid.PerfDiag).
When you have an unquali...
Script entire database SQL-Server
Is there a way I can get a scripting of all tables, procs, and other objects from a database? I know there's an option to script the database but it only gave me some sort of top level script, certainly not a script to create all tables, procs, udfs, .etc.
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