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...
在iOS开发过程中,Xcode是必不可少的工具,用于构建、测试和发布应用程序。然而,随着Xcode版本的更新,开发者可能会遇到与旧版本兼容性的...同时,利用好社区资源和依赖管理工具,可以极大地减轻这种问题带来的困扰。
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...