With theCOLLATEclause, you can override whatever the default collation is for a comparison.COLLATEmay be used in various parts of SQL statements. Here are some examples: WithORDER BY: SELECTkFROMt1ORDERBYkCOLLATElatin1_german2_ci; WithAS: ...
1.2.14 SQL Functions Oracle Database Lite does not support trigonometric functions, SOUNDEX, or bit operations. 1.2.15 Locking and Transactions Oracle Database Lite begins a transaction with the first use of SELECT. In some isolation levels, the use of a SELECT on one connection can lock...
When retrieving these to a listview I wish to limit the documents shown to only one version. Doing so means that I am only to show one document with the same id. I only get the id and name to show in the listview so I thought that distinct might do the trick. But since the name ...
select dept.name,count(teacher.name)from teacher right join dept on dept.id=teacher.dept group by dept.name; Use CASE to show thenameof each teacher followed by ‘Sci’ if the teacher is indept1 or 2 and ‘Art’ otherwise. 代码语言:javascript 代码运行次数:0 运行 AI代码解释 select teache...
c# how do i set entire worksheet to ignored errors=true code is called in controller create C# LINQ How to Delete a row from database table... Convert the SQL Statement. C# LINQ Statement that SELECT records between dates C# list search using StartsWith and Wildcard *, is that possible?
(SELECT DISTINCT Calendar_Week_Number Week, Calendar_Year Year FROM Times WHERE Calendar_Year in (2000, 2001) AND Calendar_Week_Number BETWEEN 20 AND 30 ) t ON (v.week = t.week AND v.Year = t.Year) ORDER BY t.year, t.week; ...
mysql> SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user; +---+ | query | +---+ | User: 'root'@'%'; | | User: 'root'@'localhost'; | +---+ 9 rows in set (0.00 sec)
The default output format is different (more concise) when you runmysqlin batch mode than when you use it interactively. For example, the output ofSELECT DISTINCT species FROM petlooks like this whenmysqlis run interactively: +---+ | species | +---+ | bird | | cat | | dog | | ha...
选择性(Selectivity):列唯一键(Distinct_Keys)与行数(Num_Rows)的比值。 select count(distinct column_name) as cardinality, count(*) as total_rows, count(distinct column_name) / count(*) * 100 as selectivity from table_name; 择性的过低可能导致执行计划不选择索引。那么如何理解呢?
SELECT DISTINCT vend_id tells Oracle to only return distinct (unique) vend_id rows, and so only 4 rows are returned, as shown in the following output. If you use it, you must place the DISTINCT keyword directly in front of the column names: Output +---+ | vend_id | +---+ | 10...