oracle – 比较具有大量列的两个表
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我已经搜刮过,并没有找到办理方案,必要对这么多罗列办较量. 我有1个大表(ruleTable)与ca. 300列和1723行以及另一个表(sampleTable),个中包括1行和完全沟通的列. 所需的功效是一个包括1723行和3列的表:RULE_ID,WRONG(具有沟通值的列数),RIGHT((具有差异值的列数) 直到此刻我写了一个措施(你可以在下面看到它),但它必定会变慢,完成使命必要很长时刻.有人知道怎样改造这种要领(可能也许完全改变)并应对这个题目?最大的题目是列数…… PROCEDURE MAKE_CLASSIFICATION(sampleTable VARCHAR2,ruleTable VARCHAR2) AS
l_query VARCHAR2(10000) := '';
l_rulesColumns TEXTLIST := GetFeatureColumnList(ruleTable);
l_rulesIDs TEXTLIST := GetTableColumnValues(ruleTable,'ID');
rule_value NUMBER;
sample_value NUMBER;
right NUMBER := 0;
wrong NUMBER := 0;
BEGIN
FOR j IN 1..l_rulesIDs.count()
LOOP
FOR i IN 1..l_rulesColumns.count()
LOOP
l_query := 'SELECT ' || l_rulesColumns(i) || ' FROM ' || ruleTable || ' WHERE ID=' || l_rulesIDs(j);
EXECUTE IMMEDIATE l_query INTO rule_value;
l_query := 'SELECT ' || l_rulesColumns(i) || ' FROM ' || sampleTable || ' WHERE rownum=1';
EXECUTE IMMEDIATE l_query INTO sample_value;
IF(rule_value = sample_value) THEN right:=right+1;
ELSE wrong := wrong + 1;
END IF;
END LOOP;
DBMS_output.put_line('right: ' || right || '; wrong: ' || wrong );
wrong := 0;
right := 0;
END LOOP;
END;
范例TEXTLIST是全局界说的: TYPE TEXTLIST IS VARRAY(1000000) OF VARCHAR2(10000); GetFeatureColumnList – >此函数返回带有表colmun名称列表的TEXTLIST(没有’ID’列) GetTableColumnValues – >此函数返回TEXTLIST,个中列出了COLUMN的全部值(在我们的例子中 – 列’ID’) 提前感激您的辅佐伴侣. 办理要领您可以行使要领4动态sql,使您可以或许以编程方法轮回遍历每列见:http://www.oracle-developer.net/display.php?id=422 和How to loop through columns in an oracle pl/sql cursor 要么 怎样行使user_tab_cols动态建设单个语句 ….譬喻. CREATE OR REPLACE PROCEDURE make_classification (sampletable VARCHAR2,ruletable VARCHAR2)
AS
l_query VARCHAR2 (10000) := '';
right NUMBER := 0;
wrong NUMBER := 0;
l_number_of_columns NUMBER :=0;
TYPE cur_typ IS REF CURSOR;
c cur_typ;
BEGIN
l_query:='SELECT ';
FOR rec in (SELECT column_name FROM user_tab_cols WHERE table_name=UPPER(ruleTable))
LOOP
IF l_number_of_columns > 0 THEN
l_query:=l_query||'+';
END IF;
l_query:=l_query||'DECODE(t1.'||rec.column_name||',t2.'||rec.column_name||',1,0)';
l_number_of_columns :=l_number_of_columns +1;
END LOOP;
l_query := l_query || ' AS cnt FROM '||ruletable||' t1,'|| sampletable || ' t2';
--DBMS_OUTPUT.put_line (l_query);
OPEN c FOR l_query;
LOOP
FETCH c INTO right;
DBMS_OUTPUT.put_line ('right: ' || to_char(right) || '; wrong: ' || to_char(l_number_of_columns-right));
EXIT WHEN c%NOTFOUND;
END LOOP;
CLOSE c;
END;
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