[CALCITE-6325] Add LOG function (enabled in Mysql and Spark library) #3789
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| @@ -512,8 +512,7 @@ public enum BuiltInMethod { | |||
| SAFE_DIVIDE(SqlFunctions.class, "safeDivide", double.class, double.class), | |||
| SAFE_MULTIPLY(SqlFunctions.class, "safeMultiply", double.class, double.class), | |||
| SAFE_SUBTRACT(SqlFunctions.class, "safeSubtract", double.class, double.class), | |||
| LOG(SqlFunctions.class, "log", long.class, long.class), | |||
| LOG2(SqlFunctions.class, "log2", long.class), | |||
| LOG(SqlFunctions.class, "log", long.class, long.class, int.class), | |||
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Maybe this requires an enum instead of a numeric flag?
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@tanclary I'm sorry that it took so long to improve it. If you have time, please review this PR.
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| map.put(LN, new LogImplementor()); | ||
| map.put(LOG, new LogImplementor()); | ||
| map.put(LOG10, new LogImplementor()); | ||
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| map.put(LOG_MYSQLSPARK, new LogMysqlSparkImplementor()); |
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The SQL function name that you are registering is LOG, which is the same as what is added on line 651. The equals and hashCode methods used for the key is from the class SqlOperator and will only use the name+kind.
The result is that you overwrite the map entry from line 651. One way around this is set LOG_MYSQLSPARK to a new anonymous inner subclass of SqlBasicFunction. You would need to increase visibility of the SqlBasicFunction constructor.
LOG_MYSQLSPARK = new SqlBasicFunction(...) {};
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@normanj-bitquill Yes, you are right, so I use the name LOGMYSQLSPARK. The method you mentioned is something I didn't expect. Let me try it.
Thank you for your reply
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The issue isn't with the static variable name, it is with the value of name in the SqlBasicFunction object. Both LOG and LOG_MYSQLSPARK use the same value for the name (and for kind).
If you debug at this point, you can see if it is replacing or adding a new entry.
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fix,
public static final SqlFunction LOG_MYSQL =
SqlBasicFunction.create(SqlKind.LOG,
ReturnTypes.DOUBLE_FORCE_NULLABLE,
OperandTypes.NUMERIC_OPTIONAL_NUMERIC);
Changing the parameter list can fix this situation
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@normanj-bitquill I'm very sorry for the late reply. I've been very busy recently. You are correct, but I have a question, why the test can pass
Thanks for reminding me
| @@ -211,6 +211,7 @@ | |||
| import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOG2; | |||
| import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOGICAL_AND; | |||
| import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOGICAL_OR; | |||
| import static org.apache.calcite.sql.fun.SqlLibraryOperators.LOG_MYSQLSPARK; | |||
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It is strange we use LOG_MYSQLSPARK. May be LOG_SPARK or LOG_MYSQL. we will add the libraries label in SqlLibraryOperators to show the function can work in which database.
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Bigquery's log function and MySQL's log function are inconsistent in log(0)
| @@ -2214,6 +2222,7 @@ private static RelDataType deriveTypeMapFromEntries(SqlOperatorBinding opBinding | |||
| OperandTypes.NUMERIC, | |||
| SqlFunctionCategory.NUMERIC); | |||
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site/_docs/reference.md
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| @@ -2789,7 +2789,8 @@ In the following: | |||
| | f s | LEN(string) | Equivalent to `CHAR_LENGTH(string)` | |||
| | b f s | LENGTH(string) | Equivalent to `CHAR_LENGTH(string)` | |||
| | h s | LEVENSHTEIN(string1, string2) | Returns the Levenshtein distance between *string1* and *string2* | |||
| | b | LOG(numeric1 [, numeric2 ]) | Returns the logarithm of *numeric1* to base *numeric2*, or base e if *numeric2* is not present | |||
| | b p | LOG(numeric1 [, numeric2 ]) | Returns the logarithm of *numeric1* to base *numeric2*, or base e if *numeric2* is not present | |||
| | m s | LOG(numeric1 [, numeric2 ]) | Returns the logarithm of *numeric1* to base *numeric2*, or base e if *numeric2* is not present | |||
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Need to add a description to illustrate the difference before LOG.
Co-authored-by: Tanner Clary <tannerclary@google.com>
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https://issues.apache.org/jira/browse/CALCITE-6325