Mysql and Oracle Database concat () functions, oracleconcat

Mysql and Oracle Database concat () functions, oracleconcat

I. Different Function Parameters

Mysql supports concatenation of multiple strings:

CONCAT (str1, str2 ,...)

Oralce only supports concatenation of two strings. To splice multiple strings, you can use concat

CONCAT (str1, str2)

2. The processing methods for Null parameters are different.

Mysql: returns the string generated by the connection parameter. If any parameter is NULL, the return value is NULL.

Oralce: returns the concatenated string if any parameter is NULL.

Iii. Other aspects

Mysql: If all parameters are non-binary strings, the result is a non-binary string.
If the independent variable contains any binary string, the result is a binary string.

Oracle: If the connected value in CONCAT is not a string, Oracle will try to convert it to a string

Note: The Oracle concatenation string can also use "|". If the parameter is Null, the return value is the concatenation string.