介绍一种使用TYPE方式,解决IN列表过程的问题。
Oracle的in操作,最多支持1000个对象,如果超过这个值,则会报错:
SQL> CREATE TABLE T AS SELECT ROWNUM ID, OBJECT_NAME, OBJECT_TYPE FROM DBA_OBJECTS;
表已创建。
SQL> SELECT COUNT(*) FROM T
2 WHERE ID IN
3 (
4 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,
5 22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
6 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,
7 58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,
8 76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,
9 94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,
10 109,110,111,112,113,114,115,116,117,118,119,120,121,122,
11 123,124,125,126,127,128,129,130,131,132,133,134,135,136,
12 137,138,139,140,141,142,143,144,145,146,147,148,149,150,
13 151,152,153,154,155,156,157,158,159,160,161,162,163,164,
14 165,166,167,168,169,170,171,172,173,174,175,176,177,178,
15 179,180,181,182,183,184,185,186,187,188,189,190,191,192,
16 193,194,195,196,197,198,199,200,201,202,203,204,205,206,
17 207,208,209,210,211,212,213,214,215,216,217,218,219,220,
18 221,222,223,224,225,226,227,228,229,230,231,232,233,234,
19 235,236,237,238,239,240,241,242,243,244,245,246,247,248,
20 249,250,251,252,253,254,255,256,257,258,259,260,261,262,
21 263,264,265,266,267,268,269,270,271,272,273,274,275,276,
22 277,278,279,280,281,282,283,284,285,286,287,288,289,290,
23 291,292,293,294,295,296,297,298,299,300,301,302,303,304,
24 305,306,307,308,309,310,311,312,313,314,315,316,317,318,
25 319,320,321,322,323,324,325,326,327,328,329,330,331,332,
26 333,334,335,336,337,338,339,340,341,342,343,344,345,346,
27 347,348,349,350,351,352,353,354,355,356,357,358,359,360,
28 361,362,363,364,365,366,367,368,369,370,371,372,373,374,
29 375,376,377,378,379,380,381,382,383,384,385,386,387,388,
30 389,390,391,392,393,394,395,396,397,398,399,400,401,402,
31 403,404,405,406,407,408,409,410,411,412,413,414,415,416,
32 417,418,419,420,421,422,423,424,425,426,427,428,429,430,
33 431,432,433,434,435,436,437,438,439,440,441,442,443,444,
34 445,446,447,448,449,450,451,452,453,454,455,456,457,458,
35 459,460,461,462,463,464,465,466,467,468,469,470,471,472,
36 473,474,475,476,477,478,479,480,481,482,483,484,485,486,
37 487,488,489,490,491,492,493,494,495,496,497,498,499,500,
38 501,502,503,504,505,506,507,508,509,510,511,512,513,514,
39 515,516,517,518,519,520,521,522,523,524,525,526,527,528,
40 529,530,531,532,533,534,535,536,537,538,539,540,541,542,
41 543,544,545,546,547,548,549,550,551,552,553,554,555,556,
42 557,558,559,560,561,562,563,564,565,566,567,568,569,570,
43 571,572,573,574,575,576,577,578,579,580,581,582,583,584,
44 585,586,587,588,589,590,591,592,593,594,595,596,597,598,
45 599,600,601,602,603,604,605,606,607,608,609,610,611,612,
46 613,614,615,616,617,618,619,620,621,622,623,624,625,626,
47 627,628,629,630,631,632,633,634,635,636,637,638,639,640,
48 641,642,643,644,645,646,647,648,649,650,651,652,653,654,
49 655,656,657,658,659,660,661,662,663,664,665,666,667,668,
50 669,670,671,672,673,674,675,676,677,678,679,680,681,682,
51 683,684,685,686,687,688,689,690,691,692,693,694,695,696,
52 697,698,699,700,701,702,703,704,705,706,707,708,709,710,
53 711,712,713,714,715,716,717,718,719,720,721,722,723,724,
54 725,726,727,728,729,730,731,732,733,734,735,736,737,738,
55 739,740,741,742,743,744,745,746,747,748,749,750,751,752,
56 753,754,755,756,757,758,759,760,761,762,763,764,765,766,
57 767,768,769,770,771,772,773,774,775,776,777,778,779,780,
58 781,782,783,784,785,786,787,788,789,790,791,792,793,794,
59 795,796,797,798,799,800,801,802,803,804,805,806,807,808,
60 809,810,811,812,813,814,815,816,817,818,819,820,821,822,
61 823,824,825,826,827,828,829,830,831,832,833,834,835,836,
62 837,838,839,840,841,842,843,844,845,846,847,848,849,850,
63 851,852,853,854,855,856,857,858,859,860,861,862,863,864,
64 865,866,867,868,869,870,871,872,873,874,875,876,877,878,
65 879,880,881,882,883,884,885,886,887,888,889,890,891,892,
66 893,894,895,896,897,898,899,900,901,902,903,904,905,906,
67 907,908,909,910,911,912,913,914,915,916,917,918,919,920,
68 921,922,923,924,925,926,927,928,929,930,931,932,933,934,
69 935,936,937,938,939,940,941,942,943,944,945,946,947,948,
70 949,950,951,952,953,954,955,956,957,958,959,960,961,962,
71 963,964,965,966,967,968,969,970,971,972,973,974,975,976,
72 977,978,979,980,981,982,983,984,985,986,987,988,989,990,
73 991,992,993,994,995,996,997,998,999,1000,1001,1002,1003
74 );
991,992,993,994,995,996,997,998,999,1000,1001,1002,1003
*第 73 行出现错误:
ORA-01795: 列表中的最大表达式数为 1000
当然使用拆分表达式的方式可以实现:
SQL> SELECT COUNT(*) FROM T
2 WHERE ID IN
3 (
4 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,
5 22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
6 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,
7 58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,
8 76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,
9 94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,
10 109,110,111,112,113,114,115,116,117,118,119,120,121,122,
11 123,124,125,126,127,128,129,130,131,132,133,134,135,136,
12 137,138,139,140,141,142,143,144,145,146,147,148,149,150,
13 151,152,153,154,155,156,157,158,159,160,161,162,163,164,
14 165,166,167,168,169,170,171,172,173,174,175,176,177,178,
15 179,180,181,182,183,184,185,186,187,188,189,190,191,192,
16 193,194,195,196,197,198,199,200,201,202,203,204,205,206,
17 207,208,209,210,211,212,213,214,215,216,217,218,219,220,
18 221,222,223,224,225,226,227,228,229,230,231,232,233,234,
19 235,236,237,238,239,240,241,242,243,244,245,246,247,248,
20 249,250,251,252,253,254,255,256,257,258,259,260,261,262,
21 263,264,265,266,267,268,269,270,271,272,273,274,275,276,
22 277,278,279,280,281,282,283,284,285,286,287,288,289,290,
23 291,292,293,294,295,296,297,298,299,300,301,302,303,304,
24 305,306,307,308,309,310,311,312,313,314,315,316,317,318,
25 319,320,321,322,323,324,325,326,327,328,329,330,331,332,
26 333,334,335,336,337,338,339,340,341,342,343,344,345,346,
27 347,348,349,350,351,352,353,354,355,356,357,358,359,360,
28 361,362,363,364,365,366,367,368,369,370,371,372,373,374,
29 375,376,377,378,379,380,381,382,383,384,385,386,387,388,
30 389,390,391,392,393,394,395,396,397,398,399,400,401,402,
31 403,404,405,406,407,408,409,410,411,412,413,414,415,416,
32 417,418,419,420,421,422,423,424,425,426,427,428,429,430,
33 431,432,433,434,435,436,437,438,439,440,441,442,443,444,
34 445,446,447,448,449,450,451,452,453,454,455,456,457,458,
35 459,460,461,462,463,464,465,466,467,468,469,470,471,472,
36 473,474,475,476,477,478,479,480,481,482,483,484,485,486,
37 487,488,489,490,491,492,493,494,495,496,497,498,499,500,
38 501,502,503,504,505,506,507,508,509,510,511,512,513,514,
39 515,516,517,518,519,520,521,522,523,524,525,526,527,528,
40 529,530,531,532,533,534,535,536,537,538,539,540,541,542,
41 543,544,545,546,547,548,549,550,551,552,553,554,555,556,
42 557,558,559,560,561,562,563,564,565,566,567,568,569,570,
43 571,572,573,574,575,576,577,578,579,580,581,582,583,584,
44 585,586,587,588,589,590,591,592,593,594,595,596,597,598,
45 599,600,601,602,603,604,605,606,607,608,609,610,611,612,
46 613,614,615,616,617,618,619,620,621,622,623,624,625,626,
47 627,628,629,630,631,632,633,634,635,636,637,638,639,640,
48 641,642,643,644,645,646,647,648,649,650,651,652,653,654,
49 655,656,657,658,659,660,661,662,663,664,665,666,667,668,
50 669,670,671,672,673,674,675,676,677,678,679,680,681,682,
51 683,684,685,686,687,688,689,690,691,692,693,694,695,696,
52 697,698,699,700,701,702,703,704,705,706,707,708,709,710,
53 711,712,713,714,715,716,717,718,719,720,721,722,723,724,
54 725,726,727,728,729,730,731,732,733,734,735,736,737,738,
55 739,740,741,742,743,744,745,746,747,748,749,750,751,752,
56 753,754,755,756,757,758,759,760,761,762,763,764,765,766,
57 767,768,769,770,771,772,773,774,775,776,777,778,779,780,
58 781,782,783,784,785,786,787,788,789,790,791,792,793,794,
59 795,796,797,798,799,800,801,802,803,804,805,806,807,808,
60 809,810,811,812,813,814,815,816,817,818,819,820,821,822,
61 823,824,825,826,827,828,829,830,831,832,833,834,835,836,
62 837,838,839,840,841,842,843,844,845,846,847,848,849,850,
63 851,852,853,854,855,856,857,858,859,860,861,862,863,864,
64 865,866,867,868,869,870,871,872,873,874,875,876,877,878,
65 879,880,881,882,883,884,885,886,887,888,889,890,891,892,
66 893,894,895,896,897,898,899,900,901,902,903,904,905,906,
67 907,908,909,910,911,912,913,914,915,916,917,918,919,920,
68 921,922,923,924,925,926,927,928,929,930,931,932,933,934,
69 935,936,937,938,939,940,941,942,943,944,945,946,947,948,
70 949,950,951,952,953,954,955,956,957,958,959,960,961,962,
71 963,964,965,966,967,968,969,970,971,972,973,974,975,976,
72 977,978,979,980,981,982,983,984,985,986,987,988,989,990,
73 991,992,993,994,995,996,997,998,999,1000)
74 OR ID IN (1001,1002,1003);
COUNT(*)
----------
1003
用UNION的方式也可以达到上面的效果,不过这种方式存在一个问题,如果IN列表的数据量很大,那么SQL将使用OR或UNION分成多个部分,而且必须确保每个部分的IN列表中的数量都不超过1000,这是很难通过程序来进行控制的。
通过使用TYPE,来构造一个嵌套表的方式,可以彻底解决上面的问题:
SQL> CREATE OR REPLACE TYPE T_IN IS TABLE OF NUMBER;
2 /
类型已创建。
SQL> CREATE OR REPLACE FUNCTION F_TO_T_IN (P_IN VARCHAR2) RETURN T_IN AS
2 V_RETURN T_IN DEFAULT T_IN();
3 V_IN VARCHAR2(32767);
4 V_COUNT NUMBER DEFAULT 0;
5 BEGIN
6 V_IN := REPLACE(P_IN || ',', CHR(10), '');
7 WHILE(INSTR(V_IN, ',') > 0) LOOP
8 V_RETURN.EXTEND;
9 V_COUNT := V_COUNT + 1;
10 V_RETURN(V_COUNT) := SUBSTR(V_IN, 1, INSTR(V_IN, ',') - 1);
11 V_IN := SUBSTR(V_IN, INSTR(V_IN, ',') + 1);
12 END LOOP;
13 RETURN V_RETURN;
14 END;
15 /
函数已创建。
SQL> SELECT COUNT(*) FROM T A, TABLE(SELECT F_TO_T_IN(
2 '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,
3 22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,
4 40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,
5 58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,
6 76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,
7 94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,
8 109,110,111,112,113,114,115,116,117,118,119,120,121,122,
9 123,124,125,126,127,128,129,130,131,132,133,134,135,136,
10 137,138,139,140,141,142,143,144,145,146,147,148,149,150,
11 151,152,153,154,155,156,157,158,159,160,161,162,163,164,
12 165,166,167,168,169,170,171,172,173,174,175,176,177,178,
13 179,180,181,182,183,184,185,186,187,188,189,190,191,192,
14 193,194,195,196,197,198,199,200,201,202,203,204,205,206,
15 207,208,209,210,211,212,213,214,215,216,217,218,219,220,
16 221,222,223,224,225,226,227,228,229,230,231,232,233,234,
17 235,236,237,238,239,240,241,242,243,244,245,246,247,248,
18 249,250,251,252,253,254,255,256,257,258,259,260,261,262,
19 263,264,265,266,267,268,269,270,271,272,273,274,275,276,
20 277,278,279,280,281,282,283,284,285,286,287,288,289,290,
21 291,292,293,294,295,296,297,298,299,300,301,302,303,304,
22 305,306,307,308,309,310,311,312,313,314,315,316,317,318,
23 319,320,321,322,323,324,325,326,327,328,329,330,331,332,
24 333,334,335,336,337,338,339,340,341,342,343,344,345,346,
25 347,348,349,350,351,352,353,354,355,356,357,358,359,360,
26 361,362,363,364,365,366,367,368,369,370,371,372,373,374,
27 375,376,377,378,379,380,381,382,383,384,385,386,387,388,
28 389,390,391,392,393,394,395,396,397,398,399,400,401,402,
29 403,404,405,406,407,408,409,410,411,412,413,414,415,416,
30 417,418,419,420,421,422,423,424,425,426,427,428,429,430,
31 431,432,433,434,435,436,437,438,439,440,441,442,443,444,
32 445,446,447,448,449,450,451,452,453,454,455,456,457,458,
33 459,460,461,462,463,464,465,466,467,468,469,470,471,472,
34 473,474,475,476,477,478,479,480,481,482,483,484,485,486,
35 487,488,489,490,491,492,493,494,495,496,497,498,499,500,
36 501,502,503,504,505,506,507,508,509,510,511,512,513,514,
37 515,516,517,518,519,520,521,522,523,524,525,526,527,528,
38 529,530,531,532,533,534,535,536,537,538,539,540,541,542,
39 543,544,545,546,547,548,549,550,551,552,553,554,555,556,
40 557,558,559,560,561,562,563,564,565,566,567,568,569,570,
41 571,572,573,574,575,576,577,578,579,580,581,582,583,584,
42 585,586,587,588,589,590,591,592,593,594,595,596,597,598,
43 599,600,601,602,603,604,605,606,607,608,609,610,611,612,
44 613,614,615,616,617,618,619,620,621,622,623,624,625,626,
45 627,628,629,630,631,632,633,634,635,636,637,638,639,640,
46 641,642,643,644,645,646,647,648,649,650,651,652,653,654,
47 655,656,657,658,659,660,661,662,663,664,665,666,667,668,
48 669,670,671,672,673,674,675,676,677,678,679,680,681,682,
49 683,684,685,686,687,688,689,690,691,692,693,694,695,696,
50 697,698,699,700,701,702,703,704,705,706,707,708,709,710,
51 711,712,713,714,715,716,717,718,719,720,721,722,723,724,
52 725,726,727,728,729,730,731,732,733,734,735,736,737,738,
53 739,740,741,742,743,744,745,746,747,748,749,750,751,752,
54 753,754,755,756,757,758,759,760,761,762,763,764,765,766,
55 767,768,769,770,771,772,773,774,775,776,777,778,779,780,
56 781,782,783,784,785,786,787,788,789,790,791,792,793,794,
57 795,796,797,798,799,800,801,802,803,804,805,806,807,808,
58 809,810,811,812,813,814,815,816,817,818,819,820,821,822,
59 823,824,825,826,827,828,829,830,831,832,833,834,835,836,
60 837,838,839,840,841,842,843,844,845,846,847,848,849,850,
61 851,852,853,854,855,856,857,858,859,860,861,862,863,864,
62 865,866,867,868,869,870,871,872,873,874,875,876,877,878,
63 879,880,881,882,883,884,885,886,887,888,889,890,891,892,
64 893,894,895,896,897,898,899,900,901,902,903,904,905,906,
65 907,908,909,910,911,912,913,914,915,916,917,918,919,920,
66 921,922,923,924,925,926,927,928,929,930,931,932,933,934,
67 935,936,937,938,939,940,941,942,943,944,945,946,947,948,
68 949,950,951,952,953,954,955,956,957,958,959,960,961,962,
69 963,964,965,966,967,968,969,970,971,972,973,974,975,976,
70 977,978,979,980,981,982,983,984,985,986,987,988,989,990,
71 991,992,993,994,995,996,997,998,999,1000,1001,1002,1003'
72 ) FROM DUAL) B
73 WHERE A.ID = B.COLUMN_VALUE
74 ;
COUNT(*)
----------
1003
这种方式对IN的列表数量没有限制,当然,当前给出的例子很简单,只是针对NUMBER类型的,而且使用VARCHAR2类型来传递列表的值,仍然存在长度的限制,只需要将过程稍微修改一下,改为CLOB类型作为参数,就不在存在长度的限制。至于其他数据类型的实现,方法与此大同小异,这里就不重复了。
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例如,在进行分组统计、动态构建复杂查询等情况时,如果涉及大量的字段或条件,可能会导致SQL语句过长而无法执行。 #### 解决方案一:分批次执行SQL 一种常见的解决方案是通过将长SQL语句拆分成多个较短的SQL语句...
JavaScript中的数组在解析引擎中的实现方式对于理解"Edge Type Confusion利用1"至关重要。JavaScript是一种弱类型语言,这意味着数组可以存储不同类型的数据,如数字、字符串、对象等。然而,在底层,这种灵活性带来...
贝叶斯反问题是应用概率统计理论解决反问题的一种方法。在统计学和计算数学中,反问题(Inverse Problem)是指根据给定的输出(或效应)推断出引起这一输出的原因的过程。与之相对的,正问题(Forward Problem)则是...
在现代的计算机科学和工程领域,模糊逻辑已经成为解决复杂系统控制问题的重要工具。MatlabC2.rar 文件集合提供了一组针对二型模糊系统(Type-2 Fuzzy Systems)的代码,这为理解和实践模糊控制提供了强大的支持。本...
他们通过丰富的实例和实际应用来展示如何利用AspectJ解决实际问题,从而提高软件开发的效率和质量。 关于“源码”标签,书中可能涵盖了如何阅读和理解AspectJ编译后的字节码,以及如何将AspectJ集成到现有的Java...
总结,解决Django中多条件查询的问题,可以利用字典构建查询条件,结合Django ORM的`filter()`方法,实现动态、灵活的查询。这种方法简单易懂,适用于多种场景,特别是当查询条件数量不确定时。同时,前端与后端的...
此外,Kotlin的协程(coroutines)机制为解决异步编程问题提供了新的解决方案,使得开发者可以编写出类似同步代码的异步逻辑,避免了回调地狱。 在面向对象编程方面,《Kotlin in Action》详细阐述了类、对象、接口...
经典遗传算法(SGA)是一种基于生物进化理论的全局优化技术,它在寻找非线性最优化问题的解决方案中有着广泛的应用。遗传算法模仿了自然界中的物种进化过程,通过选择、交叉和变异等操作,逐步优化种群,逼近最优解...
为了解决这个问题,我们可以利用MySQL中的一个特殊函数FIND_IN_SET()。这个函数用于返回一个字符串str在由逗号分隔的字符串列表strlist中的位置索引。当str在strlist中出现时,FIND_IN_SET(str,strlist)函数返回一个...
为了解决这个问题,开发者通常会利用JavaScript来实现跨浏览器的`placeholder`兼容性处理。 标题"javascript版placeholder解决一些浏览器不支持placeholder属性的问题"指的就是通过JavaScript来模拟`placeholder`的...
### 关于解决jQuery同步异步的问题 在前端开发过程中,我们经常会使用到jQuery库来进行DOM操作及Ajax请求等。而在处理Ajax请求时,默认情况下jQuery的`$.ajax()`方法是采用异步的方式执行的,这对于大部分场景来说...
解决这个问题非常简单,只需要将创建表语句中的`TYPE=MyISAM`改为`ENGINE=MyISAM`即可。这样做不仅可以确保语法正确,同时也能保证你的代码遵循了最新的MySQL规范。 MyISAM和InnoDB是MySQL中最常见的两种存储引擎,...
为了解决这一问题,我们可以利用Nginx作为反向代理服务器,将前端的请求转发到后端,从而规避同源策略的限制。 Nginx是一款高性能的HTTP和反向代理服务器,具备异步非阻塞的处理能力,常用于处理高并发场景。在处理...
在这个过程中,我们并不涉及远程编译,而是利用本地VScode与远程Linux环境中的gdbserver协同工作来完成调试。 首先,确保在远程Linux系统上安装了必要的软件,包括gdb和gdbserver。在Ubuntu系统中,可以通过`sudo ...
根据提供的文档信息,本文将详细解析如何利用IDA*(Iterative Deepening A*)算法解决经典的搬运工问题,并深入探讨其算法实现与优化过程。 ### 搬运工问题简介 搬运工问题(Sokoban)是一款益智类游戏,玩家需要...
该方法考虑了机电系统中的非线性特性,利用Type-2模糊逻辑强大的不确定性处理能力,提高控制系统的精确度和鲁棒性。该研究领域可能包括模糊集合理论、模糊规则的生成和优化、模糊系统的稳定性分析、以及模糊控制器的...
在解读这篇关于新型煤粉稳燃器流场...在实际应用层面,这项研究的成果可能将对电厂锅炉设计产生重要影响,提高能源利用率,降低环境污染。同时,也能够为从事相关领域研究的工程师和科研人员提供理论依据和研究方向。