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How to update column with null value
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No special syntax:
CREATE TABLE your_table (some_id int, your_column varchar(100));
INSERT INTO your_table VALUES (1, 'Hello');
UPDATE your_table
SET your_column = NULL
WHERE some_id = 1;
SELECT * FROM your_table WHERE your_column IS NULL;
+---...
INSERT with SELECT
...unning select next time? if I want to insert and get the result of courses table
– TAHA SULTAN TEMURI
Oct 8 '19 at 13:05
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How to create a backup of a single table in a postgres database?
Is there a way to create a backup of a single table within a database using postgres? And how? Does this also work with the pg_dump command?
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Does MySQL ignore null values on unique constraints?
... MySQL allows multiple NULLs in a column with a unique constraint.
CREATE TABLE table1 (x INT NULL UNIQUE);
INSERT table1 VALUES (1);
INSERT table1 VALUES (1); -- Duplicate entry '1' for key 'x'
INSERT table1 VALUES (NULL);
INSERT table1 VALUES (NULL);
SELECT * FROM table1;
Result:
x
NULL
NULL...
How to get line count of a large file cheaply in Python?
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is wccount in this table for the subprocess shell wc tool?
– Anentropic
Nov 11 '15 at 18:05
1
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In a bootstrap responsive page how to center a div
...http://getbootstrap.com/dist/css/bootstrap.css');
html, body, .container-table {
height: 100%;
}
.container-table {
display: table;
}
.vertical-center-row {
display: table-cell;
vertical-align: middle;
}
<script src="http://cdnjs.cloudflare.com/ajax/libs/twitter-bootst...
Get the new record primary key ID from MySQL insert query?
Let's say I am doing a MySQL INSERT into one of my tables and the table has the column item_id which is set to autoincrement and primary key .
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Postgres dump of only parts of tables for a dev snapshot
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On your larger tables you can use the COPY command to pull out subsets...
COPY (SELECT * FROM mytable WHERE ...) TO '/tmp/myfile.tsv'
COPY mytable FROM 'myfile.tsv'
https://www.postgresql.org/docs/current/static/sql-copy.html
You shoul...
Clustered vs Non-Clustered
... PersonId means that the rows will be physically sorted by PersonId in the table, allowing an index search on this to go straight to the row (rather than a non-clustered index, which would direct you to the row's location, adding an extra step).
That said, it's unusual for the primary key not to be...
Using an RDBMS as event sourcing storage
...1 and 2 at all.
Below is the schema as used in Ncqrs. As you can see, the table "Events" stores the related data as a CLOB (i.e. JSON or XML). This corresponds to your option 3 (Only that there is no "ProductEvents" table because you only need one generic "Events" table. In Ncqrs the mapping to you...