在讲到3.8.2 The With Clause 这部分时,书中给出的例题是“Find all branches where the total account deposit is greater than the average of the total account deposits at all branches”翻译成中文大概意思是:找出所有支行,其存款总额大于总的平均存款。 书中给出的例程,blablabla的敲上去以后居然会报错。
TheELSEclause has no condition as it is executed if none of theWHENconditions are matched. For example, -- CASE condition with ELSE clause in SQLSELECTcustomer_id, first_name,CASEWHENcountry ='USA'THEN'United States of America'WHENcountry ='UK'THEN'United Kingdom'ELSE'Unknown Country'ENDASc...
Use recursion or hierarchical queries. The SQL WITH clause allows you to write recursive queries, or hierarchical queries, which are queries that refer to previous rows of the same query. We’ll look at this a little later in this article. Here’s my YouTube video on using Common Table Ex...
We can update all the rows in a table at once by omitting theWHEREclause. For example, -- update all rowsUPDATECustomersSETcountry ='NP'; Run Code Here, the SQL command changes the value of thecountrycolumn toNPfor all rows. Note:We should be cautious while using theUPDATEstatement. If...
To keep it simple, the following example only references the aggregations once, where the SQL “WITH clause” is normally used when an aggregation is referenced multiple times in a query. We can also use the SQL-99 “WITH clause” instead of temporary tables. The Oracle SQL “WITH clause”...
However, if I include the with clause like below: with my_table as ( select a.dataId, a.my_no, b.my_attribute from myDB.table_a a left join myDB.table_b b on a.my_no = b.my_no order by dataId ) select * from my_table I got the following error: Erro...
query. The syntax of the query differs depending on the data source you are using, as it is in the native format of the database or data source. An application can use the ISQLSyntax interface on a Workspace to determine information about the SQL syntax u 表示指定与WhereClause物产是SQL...
Expressions in SQL with Examples In this article, we will learn about expressions in SQL and implement some examples to demonstrate Boolean, numeric, and date-time expressions. 1. Boolean Expressions The use of Boolean expressions is mainly done in the where clause of the SQL queries which can...
Example 4: Using unnest with a non-path expression This is an example where the unnesting expression is not a path expression, and as a result, the UNNEST clause cannot be used. For example, a user may have multiple phone numbers in the same area code. To determine the num...
GROUP BYis a clause in SQL that is only used with aggregate functions (COUNT, MAX, MIN, SUM, AVG). It is used in collaboration with the SELECT statement to arrange identical data into groups. SELECT column_name, COUNT(*) FROM table_name ...