21 lines
666 B
Plaintext
21 lines
666 B
Plaintext
drop table if exists t1;
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create table t1 (t1 char(3) primary key);
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insert into t1 values("ABC");
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insert into t1 values("ABA");
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insert into t1 values("AB%");
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select * from t1 where t1="ABC";
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t1
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ABC
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select * from t1 where t1="ABCD";
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t1
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select * from t1 where t1 like "a_\%";
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t1
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AB%
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describe select * from t1 where t1="ABC";
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 const PRIMARY PRIMARY 3 const 1 Using index
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describe select * from t1 where t1="ABCD";
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
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drop table t1;
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