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”...
WITH subquery_name AS (the aggregation SQL statement) SELECT (query naming subquery_name); Retuning to our oversimplified example, let's replace the temporary tables with the SQL "WITH clause" (Note: You may find a faster execution plan by using Global Temporary tables, depending on your rele...
The syntax for the WHERE clause in Oracle/PLSQL is: WHERE conditions; Parameters or Arguments conditions The conditions that must be met for records to be selected.Example - With Single condition It is difficult to explain the syntax for the Oracle WHERE clause, so let's look at some examp...
This Oracle ORDER BY example would return all records sorted by the supplier_city field in descending order.Example - Sorting by relative position You can also use the Oracle ORDER BY clause to sort by relative position in the result set, where the first field in the result set is 1. The...
HelloDBA.com> exec sql_explain('select /*+NO_ADAPTIVE_PLAN*/* from t_tab t where table_name = any (select max(object_name) from t_obj o where o.owner=t.owner group by owner)', 'TYPICAL'); Plan hash value: 3428189515 --- | Id | Operation | Name | Rows | Bytes | Cost...
SQL macros and the WITH clause Leave a reply SQL macros and WITH clause are not known to be great friends: you cannot call a SQL macro in a WITH clause and if you want to define a table macro returning a query containing a WITH subquery(ies), then you won’t be able to use scalar...
• The SQL “WITHclause” is used when a subquery is executed multiple times • Also useful for recursive queries (SQL-99, but notOracleSQL) To keep it simple, the following example only references the aggregations once, where the SQL “WITHclause” is normally used when an aggregation ...
Here’s the syntax of theLEFT JOINwith theUSINGclause: SELECTcolumn_listFROMXLEFTJOINYUSING(id);Code language:SQL (Structured Query Language)(sql) In this example, theLEFT JOINwill check if the values in theidcolumn of theXtable is equal to the values in theidcolumn of theYtable. ...
在ORACLE数据库中,表与表之间的SQL JOIN方式有多种(不仅表与表,还可以表与视图、物化视图等联结),官方的解释如下所示 A join is a query that combines rows from two or more tables, views, or materialized views. Oracle Database performs a join whenever multiple tables appear in the FROM clause of...
Oracle Database SQL Language Reference上有关listagg()函数的描述如下: ———– Purpose For a specified measure, LISTAGG orders data within each group specified in the ORDER BY clause and then concatenates the values of the measure column. ■ As a single-set aggregate function, LISTAGG operates ...