Fill Table Column DataType is Object

(1) By anonymous on 2022-05-04 08:06:12 [link] [source]

my SQL script

SELECT RowState,0 AS click FROM abc

running DataAdapter.Fill Column click return object field,why not Int64 dataType

(2) By Simon Slavin (slavin) on 2022-05-04 08:57:18 in reply to 1 [link] [source]

Please show us the

CREATE TABLE abc …

command.

(3) By Gunter Hick (gunter_hick) on 2022-05-04 09:23:05 in reply to 1 [source]

I am assuming the question is actually "why does the column named click have no data type".

It does not have a "declared data type" because it is not a field froma table. It also has no affinity, because only certain specific types of expressions have an affinity. The constant integer 0 is not one of them.

Whatever wrapper you are using therefore has nothing to go on when attempting to determine the data type of the column (sqlite3_column_decltype returns NULL for expressions), whereas calling sqlite3_value_type() on the returned value should always return SQLITE_INTEGER.

Try reading https://sqlite.org/datatype3.html to expand your understanding of data types in SQLite.

(4) By kevinst on 2022-05-05 02:52:18 in reply to 3 [link] [source]

yes,the column datatype is object in datatable Schema ,if no data return

i will append column by codeing,because my database mixed SQLITE and MS SQL