在PL/SQL中打印字母金字塔 [英] Printing an alphabet pyramid in PL/SQL

问题描述

我有一个练习来编写一个程序，该程序可以打印出像这样的字母金字塔:

I have an exercise to write a program which prints out an alphabet pyramid like this:

    A
   ABA
  ABCBA
 ABCDCBA
ABCDFDCBA

该任务还建议使用INSTR，LPAD，UPPER.

The task also suggests using INSTR, LPAD, UPPER.

我想拥有一个包含字母表中所有字母的金字塔.但是，我发现更容易将数字放在第一位，所以:

I want to have the pyramid which contains the all the letters in the alphabet. However, I find it is easier to make it in numbers first so:

IF x in 0..25 loop
dbms_output.put_line(x);
end loop;
end; 

结果只是数字从0到25的直线.我不知道如何在数字之前添加空格，而最终需要使用字母来形成金字塔形状. 请不要给出完整的答案，我只需要一些建议和建议即可解决此任务.

The result is just a straight line of numbers from 0-25. I don't know how to add spaces before the numbers, which eventually needs to be letters, to form a the pyramid shape. Please don't give the full answer, I just need some suggestions and diretions to solve this task.

推荐答案

一种方法是生成金字塔的底面:

One way of doing this is to generate the base of the pyramid:

• CHR(n)将生成一个ASCII字符；和
• 您可以使用||连接字符串，因此str := str || CHR(65)会将A附加到字符串的末尾.
• FOR i IN [REVERSE] 1 .. repetitions LOOP 语句可以是用于遍历值.

• CHR(n) will generate an ASCII character; and
• you can concatenate strings with || so str := str || CHR(65) will append an A to the end of the string.
• The FOR i IN [REVERSE] 1 .. repetitions LOOP statement can be used to loop through values.

如果可以生成基准，则 TRANSLATE函数可以以一对一的方式用其他字符替换多个字符，因此:

If you can generate the base then the TRANSLATE function can replace multiple characters with other characters in a 1-to-1 correspondence so:

• TRANSLATE( 'ABC', 'ABC', ' A' )输出' A'
• TRANSLATE( 'ABC', 'ABC', ' AB' )输出' AB'
• TRANSLATE( 'ABC', 'ABC', 'ABC' )输出'ABC'

• TRANSLATE( 'ABC', 'ABC', ' A' ) outputs ' A'
• TRANSLATE( 'ABC', 'ABC', ' AB' ) outputs ' AB'
• TRANSLATE( 'ABC', 'ABC', 'ABC' ) outputs 'ABC'

如果您生成了金字塔的底部，则您有一个字符串，其中子字符串以这些字符开头，而您只需要适当长度的子字符串并用空格填充即可.

If you have generated the base of the pyramid then you have a string where the sub-string starts with those characters and you just need sub-string of the appropriate length padded with spaces.

DBMS_OUTPUT.PUT_LINE( string )会将字符串输出到控制台.

DBMS_OUTPUT.PUT_LINE( string ) will print a string to the console.

完整解决方案-如果您不想知道该怎么做，请不要关注该链接这

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