name)values(1,null);1rowcreated.SQL>insertintotest(id, name)values(2,'');1rowcreated.SQL>insertintotest(id, name)values(3,' ');--符号中' '有一个空格1rowcreated.SQL>insertintotest(id, name)values(4,' ');--符号中' '有两个空格1rowcreated.SQL>commit;Commitcomplete.SQL>select*...
SQL> insert into test(id, name) values(1, null); 1 row created. SQL> insert into test(id, name) values(2, ''); 1 row created. SQL> insert into test(id, name) values(3, ' '); --符号中' '有一个空格 1 row created. SQL> insert into test(id, name) values(4, ' '); -...
In this syntax, we use the equal to operator (=) to compare values. You can use other comparison operators such as>,>=,<, and<=. Additionally, you can combine multiple expressions using theANDandORoperators in the condition. Visualizing how the Oracle left join works# Suppose you have two...
SQL> create table table1(xm varchar(8)); SQL> insert into table1 values('weather'); SQL> insert into table1 values('wether'); SQL> insert into table1 values('gao'); SQL> select xm from table1 where soundex(xm)=soundex('weather'); XM weather wether --- SUBSTR 语法: SUBSTR(string...
For example, a date that occurs later in time is larger than an earlier date, and 0 or any positive number is larger than any negative number. You can use relational operators to compare numeric values or date values. For character values, comparison of single characters are based on the ...
SQL tutorial, we have reviewed the SQL (structured query language) functions COALESCE(), ISNULL(), NULLIF() and how these work in SQL Server, Oracle and PostgreSQL. There are also other ways for checking NULL values such as the IS NULL clause and there are other complex functions in ...
A special kind of key flexfield you can include in your application to support low and high values for each key segment rather than just single values. Ordinarily, a key flexfield range appears on your form as two adjacent flexfields, where the leftmost flexfield contains the low values for...
where manager_id = id(i); end loop; end; / 1.2.2 SELECT Statements that Reference Collections The BULK COLLECT INTO clause can improve the performance of queries that reference collections. You can use BULK COLLECT INTO with tables of scalar values, or tables of %TYPE values. ...
Compare it using all SQL conditions For the comparison, the selector is implicitly on the left-hand side. You just list the condition and the values to compare it to. For example, let’s extend the exam result to grade logic to also return: ...
--delete clause : Set the DELETE clause to apply to the Oracle query to be applied before importing data. Can be used multiple time. --oracle_fdw_prefetch: Set the oracle_fdw prefetch value. Larger values generally result in faster data transfer at the cost of greater memory utilisation at...