MQL5 ReferenceWorking with databasesDatabaseColumnType

DatabaseColumnType

Gets a field type by index.

ENUM_DATABASE_FIELD_TYPE  DatabaseColumnType(
   int  request,     // request handle received in DatabasePrepare
   int  column       // field index in the request
   );

Parameters

request

[in] Request handle received in DatabasePrepare().

column

[in] Field index in the request. Field numbering starts from zero and cannot exceed DatabaseColumnsCount() - 1.

Return Value

Return the field type from the ENUM_DATABASE_FIELD_TYPE enumeration. To get the error code, use GetLastError(), the possible responses are:

ERR_DATABASE_INVALID_HANDLE (5121) – invalid request handle;
ERR_DATABASE_NO_MORE_DATA (5126) – 'column' index exceeds DatabaseColumnsCount() -1.

Note

The value can be obtained only if at least one DatabaseRead() call has been preliminarily made for 'request'.

ENUM_DATABASE_FIELD_TYPE

ID	Description
DATABASE_FIELD_TYPE_INVALID	Error getting type, the error code can be obtained using int GetLastError()
DATABASE_FIELD_TYPE_INTEGER	Integer type
DATABASE_FIELD_TYPE_FLOAT	Real type
DATABASE_FIELD_TYPE_TEXT	String type
DATABASE_FIELD_TYPE_BLOB	Binary type
DATABASE_FIELD_TYPE_NULL	Special NULL type