2013年11月8日 · <> operator means not equal to in MS SQL. It compares two expressions (a comparison operator). When you compare nonnull expressions, the result is TRUE if the left …

2015年6月5日 · In SQL '%' and '_' (underscore sign) are wildcard characters. '%' replaces any number of characters - equivalent to '*' in Linux/Unix and Windows file search. '_' replaces one …

@Martin: I know, but the DBMS is relevant quite often; it's a good habit to get into. SQL Server uses '+' as a string concatenation operator, for instance. (Of course, the better solution would …

2012年7月30日 · The @CustID means it's a parameter that you will supply a value for later in your code. This is the best way of protecting against SQL injection. Create your query using …

2019年6月28日 · The other answers are correct if you're dealing with SQL Server, and it's clear that you are. But since the question title just says SQL, I should mention that there are some …

2014年4月29日 · sql server: + (infix operator), concat ( vararg function ) Edit: Now Azure SQL also supports ANSI SQL standard || operator for string concatenation. Docs link. sqlite: || (infix …

2019年6月12日 · Could someone explain the difference between % in SQL? I understand that % is a wildcard that allows you to query results with LIKE results, i.e. a% for words starting with …

2013年3月2日 · Both of them work the same way and there is absolutely no difference in terms of performance or result. If != and <> both are the same, which one should be used in SQL …

2012年8月1日 · They are also used to pass a table from a table-valued function, to pass table-based data between stored procedures or, more recently in the form of Table-valued …

2021年11月8日 · The second part of a SQL query is the name of the column you want to retrieve for each record you are getting. You can obviously retrieve multiple columns for each record, …