Oracle 如何使用正则表达式将数组中的项与数据库列中的项进行比较?
我正在尝试获取数组中的元素列表,如下所示:Oracle 如何使用正则表达式将数组中的项与数据库列中的项进行比较?,oracle,plsql,pattern-matching,bigdata,string-matching,Oracle,Plsql,Pattern Matching,Bigdata,String Matching,我正在尝试获取数组中的元素列表,如下所示: ['GRADE', 'GRATE', 'GRAPE', /*About 1000 other entries here ...*/ ] 1|'ANTERIOR' 2|'ANTEROGRADE' 3|'INGRATE' 4|'RETROGRADE' 5|'REIGN' ...|... /*About 1,000,000 other entries here*/ for entry in array: for each in column:
['GRADE', 'GRATE', 'GRAPE', /*About 1000 other entries here ...*/ ]
1|'ANTERIOR'
2|'ANTEROGRADE'
3|'INGRATE'
4|'RETROGRADE'
5|'REIGN'
...|...
/*About 1,000,000 other entries here*/
for entry in array:
for each in column:
if entry.right_match(each):
print entry
并将它们与Oracle数据库中的一列匹配,该列中包含以下条目:
['GRADE', 'GRATE', 'GRAPE', /*About 1000 other entries here ...*/ ]
1|'ANTERIOR'
2|'ANTEROGRADE'
3|'INGRATE'
4|'RETROGRADE'
5|'REIGN'
...|...
/*About 1,000,000 other entries here*/
for entry in array:
for each in column:
if entry.right_match(each):
print entry
对于G单词数组中的每个条目,我希望遍历Oracle数据库的word列,并尝试查找数组中每个条目的右侧匹配项。在本例中,数据库中的条目2、3和4都将匹配
在任何其他编程语言中,它看起来都是这样的:
['GRADE', 'GRATE', 'GRAPE', /*About 1000 other entries here ...*/ ]
1|'ANTERIOR'
2|'ANTEROGRADE'
3|'INGRATE'
4|'RETROGRADE'
5|'REIGN'
...|...
/*About 1,000,000 other entries here*/
for entry in array:
for each in column:
if entry.right_match(each):
print entry
如何在PL/SQL中执行此操作?在PL/SQL中,可以通过以下方式执行:
declare
SUBTYPE my_varchar2_t IS varchar2( 100 );
TYPE Roster IS TABLE OF my_varchar2_t;
names Roster := Roster( 'GRADE', 'GRATE', 'GRAPE');
begin
FOR c IN ( SELECT id, name FROM my_table )
LOOP
FOR i IN names.FIRST .. names.LAST LOOP
IF regexp_like( c.name, names( i ) ) THEN
DBMS_OUTPUT.PUT_LINE( c.id || ' ' || c.name );
END IF;
END LOOP;
END LOOP;
end;
/
但这是逐行处理,对于大型表来说,速度会非常慢。我认为最好采用如下方式:
create table test123 as
select 1 id ,'ANTERIOR' name from dual union all
select 2,'ANTEROGRADE' from dual union all
select 3,'INGRATE' from dual union all
select 4,'RETROGRADE' from dual union all
select 5,'REIGN' from dual ;
create type my_table_typ is table of varchar2( 100 );
/
select *
from table( my_table_typ( 'GRADE', 'GRATE', 'GRAPE' )) x
join test123 y on regexp_like( y.name, x.column_value )
;
COLUMN_VALUE ID NAME
------------- ---------- -----------
GRADE 2 ANTEROGRADE
GRATE 3 INGRATE
GRADE 4 RETROGRADE
D--n!你赢了我!我唯一要添加的是一些regexp语法,例如,regexp_LIKE(y.name,x.column_value | | |'$')只在末尾匹配。使用名称LIKE“%”| | value而不是regexp| LIKE,因为它稍微快一点。此外,还可以使用基于函数的索引来加速搜索,如前所述