f2s_type_override_nulls¶
Applies to: Oracle, MS SQL, MySql/MariaDB, PostgreSQL Drivers
Syntax
set_attribute f2s_type_override_nulls of {DriverID} {datatype} to {variable}
get_attribute f2s_type_override_nulls of {DriverID} {datatype} to {variable}
Parameter |
Description |
|---|---|
DriverID |
The ID of the driver for which this applies. In most cases, you should use _f2s_ActiveDriverID. |
datatype |
Type of data, must be: DF_ASCII, DF_BCD, DF_BINARY or DF_DATE |
variable |
Boolean variable, indicates how to handle blank data. True is blank, false is however the database would normally save the value. Default value is false. |
Description
Setting this attribute to true, forces blank/0 values for that data type to be stored as blank/0 instead of NULL (assuming the field allows NULL). For example, lets say the user tries to save a new record that has a string field that allows nulls and has no default value. Assume the user does not specify a value for this field. If this attribute is set to true, when the record is saved, that string value will stored as a blank string. If the attribute is set to false (the default), the value will be stored as NULL.
Getting this value returns whether or not blank/0 values are forced for values that might otherwise be NULL.
Datatypes and the values that can be forced to Blank/0 (instead of NULL):
Data Type |
Database Back End |
Value forced NULL |
|---|---|---|
DF_ASCII and DF_TEXT |
ALL |
‘ ‘ (one blank space) |
DF_BCD |
ALL |
0 (zero) |
DF_DATE and DF_DATETIME |
MySql |
00/00/0000 |
DF_DATE and DF_DATETIME |
Oracle and MS SQL Date |
01/01/0001 |
DF_DATE and DF_DATETIME |
PostgreSQL and MSSQL datetime |
01/01/1753 |
Examples
get_attribute
boolean bForceBlank
get_attribute f2s_type_force_nulls of _f2s_ActiveDriverId DF_ASCII to bForceBlank
set_attribute
In this example the database backend is MS SQL and a string field that allows nulls, TextNull, has been added to the Users table in the OrderEntry example. TextNull has no default value. Therefore, when a new record is saved and TextNull is not specifically given a value, the new record will have a NULL value for TextNull. When f2s_type_override_nulls is set to true, the new record will have an blank (empty string) value.
//by default, f2s_type_override_nulls is false
Send Clear to oUsers_DD
Set Field_Changed_Value of oUsers_DD Field Users.Full_Name to "Jane Doe"
Set Field_Changed_Value of oUsers_DD Field Users.LoginName to "jdoe"
Set Field_Changed_Value of oUsers_DD Field Users.Password to "password"
Set Field_Changed_Value of oUsers_DD Field Users.Rights to 1
Send Request_Save to oUsers_DD
Send Clear to oUsers_DD
set_attribute f2s_type_override_nulls of _f2s_ActiveDriverId DF_ASCII to true
Send Clear to oUsers_DD
Set Field_Changed_Value of oUsers_DD Field Users.Full_Name to "George Doe"
Set Field_Changed_Value of oUsers_DD Field Users.LoginName to "gdoe"
Set Field_Changed_Value of oUsers_DD Field Users.Password to "password"
Set Field_Changed_Value of oUsers_DD Field Users.Rights to 1
Send Request_Save to oUsers_DD
Send Clear to oUsers_DD
The values in the database, when looking at the raw data, should be NULL for Jane Doe but blank for George Doe.
Related Attributes
f2s_type_force_nulls
Replaces: Commands SET_FIELDS_NOT_NULL and GET_FIELDS_NOT_NULL