As @eggyal pointed out in comments, you can enable string concatenation with the || operator in MySQL by setting the PIPES_AS_CONCAT SQL mode. ... <看更多>

MySQL CONCAT Function: Concatenate Two or More StringsHow to Concatenate Strings in MySQL ... ... <看更多>

Steps to reproduce Currently it's possible to concatenate strings using the method ... Concat in C# doesn't translate to CONCAT() in MySQL. ... <看更多>

CONCAT will return NULL if any of the inputs are NULL. This suggests that your select thainame... is returning NULL in at least one ... ... <看更多>