functions: add char function #7486
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dbms/src/Functions/FunctionsCoding.h
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It isn't an "IP coding function".
Let's move to another test file.
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Does it really have the same behaviour? What about numbers out of ASCII range?
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I gave up implementing the same Behavior as mysql when number out of ASCII range.
It could return multiply characters, I think it's unnecessary and I don't know the internal implementation.
mysql> select char(2221111111111);
+---------------------+
| char(2221111111111) |
+---------------------+
| $��� |
+---------------------+
1 row in set (0.00 sec)
So I just took the first byte. It's easy to make it done by Column and easy to know the results.
dbms/src/Functions/FunctionsCoding.h
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Virtual call in a loop.
dbms/src/Functions/FunctionsCoding.h
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Style: ++row instead of row ++.
dbms/src/Functions/FunctionsCoding.h
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| # Encoding functions | ||
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| ## char | ||
| Accepts multiple arguments of `Number` types. Returns a string, each char of the results corresponds to the ascii character of the input numbers. It'll cast the first byte from the number, if the byte overflows the range of ascii(which is 127), it returns an unrecognized character(�). |
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We can construct UTF-8 string with this function. It's not limited for ASCII. I will test...
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| for (size_t row = 0; row < rows; ++row) | ||
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| out_vec[row * size_per_row + column_idx] = static_cast<char>(src_data_concrete->getInt(row)); |
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Ok. BTW, it's in question what variant of loop is faster - this one or permuted.
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char function like mysql. But Behavior is not exactly the same.
Our users who used MySQL a lot said to me they really need it in ClickHouse, so I create this PR.