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假设MySQL数据库表:
create table T{
k int unsigned not null auto_increment,
a date,
b varchar(24),
c int,d varchar(24),
primary key(k),unique key a_index (a DESC,b DESC),
key k1(b),key k2(c),key k3(d));
如下哪些sql语句查询能较好的利用索引?( )
  • A、select b from WHERE b like 'aaa%';
  • B、select a,b from T WHERE a='2015-10-25' ORDER BY b ASC,c ASC;
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;
  • D、select a,b,c from T WHERE a='2015-10-25' ORDER BY a,b;
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5年前上传
13个回答
  • A、select b from WHERE b like 'aaa%';

Tulip 166
4年前回答
  • A、select b from WHERE b like 'aaa%';

fed126 34
4年前回答
  • A、select b from WHERE b like 'aaa%';
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;

4年前回答
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;

vito 8
4年前回答
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;
  • D、select a,b,c from T WHERE a='2015-10-25' ORDER BY a,b;

4年前回答
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;
  • D、select a,b,c from T WHERE a='2015-10-25' ORDER BY a,b;

Adamlet 32
4年前回答
  • A、select b from WHERE b like 'aaa%';
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;

zhang 29
4年前回答
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;
  • D、select a,b,c from T WHERE a='2015-10-25' ORDER BY a,b;

yuye 902
4年前回答
  • A、select b from WHERE b like 'aaa%';
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;

linan 153
4年前回答
  • A、select b from WHERE b like 'aaa%';
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;

4年前回答
  • C、select a,b,c from T WHERE a='2015-10-25' ORDER BY b ASC;
  • D、select a,b,c from T WHERE a='2015-10-25' ORDER BY a,b;

4年前回答
  • A、select b from WHERE b like 'aaa%';

scu2021 80
3年前回答
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