大约有 40,000 项符合查询结果（耗时：0.0816秒） [XML]
Count the number of occurrences of a string in a VARCHAR field?
...
This should do the trick:
SELECT
title,
description,
ROUND (
(
LENGTH(description)
- LENGTH( REPLACE ( description, "value", "") )
) / LENGTH("value")
) AS count
FROM <tab...
How do I escape a reserved word in Oracle?
In TSQL I could use something like Select [table] from tablename to select a column named "table".
5 Answers
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How to use UIScrollView in Storyboard
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Here are the steps with Auto Layout that worked for me on XCode 8.2.1.
Select Size Inspector of View Controller, and change Simulated Size to Freeform with height 1000 instead of Fixed.
Rename the view of View Controller as RootView.
Drag a Scroll View as subview of RootView and rename it as Scr...
Selecting only numeric columns from a data frame
...traightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Query to list number of records in each table in a database
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If you're using SQL Server 2005 and up, you can also use this:
SELECT
t.NAME AS TableName,
i.name as indexName,
p.[Rows],
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) * 8) / 1024 as To...
How to remove all MySQL tables from the command-line without DROP database permissions? [duplicate]
...tatements to execute it:
SET FOREIGN_KEY_CHECKS = 0;
SET @tables = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
FROM information_schema.tables
WHERE table_schema = 'database_name'; -- specify DB name here.
SET @tables = CONCAT('DROP TABLE ', @tables);
PRE...
Query grants for a table in postgres
...
I already found it:
SELECT grantee, privilege_type
FROM information_schema.role_table_grants
WHERE table_name='mytable'
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INSERT IF NOT EXISTS ELSE UPDATE?
...ike:
insert or replace into Book (ID, Name, TypeID, Level, Seen) values
((select ID from Book where Name = "SearchName"), "SearchName", ...);
Note that any field not in the insert list will be set to NULL if the row already exists in the table. This is why there's a subselect for the ID column: I...
SQL Query Where Field DOES NOT Contain $x
...t is meant to be used in subqueries or with predefined lists:
-- subquery
SELECT a FROM x WHERE x.b NOT IN (SELECT b FROM y);
-- predefined list
SELECT a FROM x WHERE x.b NOT IN (1, 2, 3, 6);
If you are searching a string, go for the LIKE operator (but this will be slow):
-- Finds all rows where...
In Ruby, is there an Array method that combines 'select' and 'map'?
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I usually use map and compact together along with my selection criteria as a postfix if. compact gets rid of the nils.
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}
=> [3, 3, 3, nil, nil, nil]
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}.compact
=> ...