ImportJsonByKey
method (DataWindows)
Description
Inserts data from a JSON string into a DataWindow control, DataStore
object, or DataWindowChild object according to the key name of the JSON
item.
The JSON string must be in the format described in the section called “Supported JSON formats” in Application Techniques.
This function will fail to import data properly, if the DataWindow
is in query mode.
Applies to
|
DataWindow type |
Method applies to |
|---|---|
|
PowerBuilder |
DataWindow control, DataWindowChild object, and |
Syntax
PowerBuilder
|
1 |
long dwcontrol.ImportJsonByKey( string json {, string error} {, DWBuffer dwbuffer {, long startrow {, long endrow } } } ) |
|
Argument |
Description |
|---|---|
|
dwcontrol |
A reference to a DataWindow control, DataStore, or |
|
json |
A string specifying the JSON data. The JSON string |
|
error (optional) |
A variable into which the returned warning or error When there are a large amount The import warning caused by data type The import error caused by DW presentation Most of the messages placed into this variable |
|
dwbuffer (optional) |
A value of the dwBuffer enumerated datatype For For DataWindow JSON: If not |
|
startrow (optional) |
The number of the first detail object in the JSON |
|
endrow (optional) |
The number of the last detail object in the JSON |
Return value
Long. Returns the number of rows that were imported if it succeeds
and one of the following negative integers if an error occurs. The return
value will count the rows imported into the primary, filter, and delete
buffers, but not the rows imported into DataWindowChild.
0 — When all of the data in the JSON string is null, or the JSON
string only contains data for DataWindowChild, or no JSON key matches with
the DataWindow column.
-1 — General error.
-2 — No rows or startrow value supplied is greater than the number
of rows in the JSON.
-3 — Invalid argument.
-4 — Invalid JSON.
-5 — JSON format error.
-6 — Unsupported DataWindow presentation style for import.
-7 — Error resolving DataWindow nesting.
The method returns null if any of the following:
-
any argument’s value is null
-
the DataWindow object (dataobject) is invalid
Usage
There is no forced conversion between strings and numbers. For
example, the number 123 in JSON string will not be imported into the
DataWindow column of char(10) type. For such case, a data type mismatch
warning will be recorded in the error argument.
A boolean value (true or false) will be converted to 0 or 1 when
imported from the JSON string to the DataWindow; however, 0 or 1 will not
be converted to a boolean value (true or false) when exported from the
DataWindow to the JSON string.
If the string length in JSON is larger than the string length in
DataWindow, the string will be truncated when imported into the
DataWindow. For example, JSON string [{“name”:”TestForTrancate”}] is
imported as “Test” when the data type of DataWindow column “name” is
char(4).
When the number value is imported from the JSON string to the
DataWindow column of number data type (with uncertain precision), the
value will have uncertain decimals, for example, 6.78 becomes
6.78000020980835 after imported from the JSON string to the
DataWindow.
Examples
This example imports data from a plain JSON string into the
corresponding column of DataWindowChild:
|
1 2 3 4 5 6 7 8 9 |
long ll_RowCount string ls_PlainJson datawindowchild ldwc_Dept dw_1.GetChild("dept_id", ldwc_Dept) ls_PlainJson = '[{"dept_id":100,"dept_name":"R & D"},{"dept_id":200,"dept_name":"Sales"}, & {"dept_id":300,"dept_name":"Finance"},{"dept_id":400,"dept_name":"Marketing"}]' ll_RowCount = ldwc_Dept.ImportJsonByKey(ls_PlainJson) |
This example imports data from a plain JSON string into the
corresponding column of DataWindowChild:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |
long ll_RowCount string ls_PlainJson, ls_Error datawindowchild ldwc_Dept dw_1.GetChild("dept_id", ldwc_Dept) ls_PlainJson = '[{"dept_id":100,"dept_name":"R & D"},{"dept_id":200,"dept_name":"Sales"}, & {"dept_id":300,"dept_name":"Finance"},{"dept_id":400,"dept_name":"Marketing"}]' ll_RowCount = ldwc_Dept.ImportJsonByKey(ls_PlainJson , ls_Error) //Checks if any error IF isnull(ll_RowCount) Then Messagebox("Error", "The method returns null") ElseIf ll_RowCount < 0 Then If len(ls_Error) > 0 Then Messagebox("Failed","Return Value: " + String(ll_RowCount) & + "~r~nWith error information:~r~n" + ls_Error) Else Messagebox("Failed","Return Value: "+String(ll_RowCount)) End If Else //Checks if any warning If len(ls_Error) > 0 Then MessageBox("Warning", "With warning information:~r~n" + ls_Error) Else MessageBox("Succeed", "Return Value: " + String(ll_RowCount) ) End If End If |
This example imports data from a plain JSON string into the primary
buffer of the DataWindow:
|
1 2 3 4 5 6 |
long ll_RowCount string ls_PlainJson ls_PlainJson = '[{"dept_id":100,"dept_name":"R & D","dept_head_id":501}, & {"dept_id":200,"dept_name":"Sales","dept_head_id":902}]' ll_RowCount = dw_Dept.ImportJsonByKey(ls_PlainJson, Primary!) |
This example imports data from dw_1 into a DataWindow JSON string,
and then imports data in rows 2 through the end from the JSON string into
dw_2 (suppose dw_1 and dw_2 have the same column names):
|
1 2 3 4 5 |
long ll_RowCount string ls_DWJson ls_DWJson = dw_1.ExportJson(true) ll_RowCount = dw_2.ImportJsonByKey(ls_DWJson, Primary!, 2) |
This example imports data (and state) in rows 1 through 10 from the
primary buffer of a DataWindow JSON string into the primary buffer of the
DataWindow:
|
1 2 3 4 5 6 7 |
long ll_RowCount string ls_DWJson //DataWindow JSON ls_DWJson = … ll_RowCount = dw_1.ImportJsonByKey(ls_DWJson, Primary!, 1, 10) |
This example imports data from a plain JSON string into the primary
buffer of the DataWindow:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 |
long ll_RowCount string ls_PlainJson, ls_Error ls_PlainJson = '[{"dept_id":100,"dept_name":"R & D","dept_head_id":501}, & {"dept_id":200,"dept_name":"Sales","dept_head_id":902}]' ll_RowCount = dw_Dept.ImportJsonByKey(ls_PlainJson, ls_Error, Primary!) //Checks if any error IF isnull(ll_RowCount) Then Messagebox("Error", "The method returns null") ElseIf ll_RowCount < 0 Then If len(ls_Error) > 0 Then Messagebox("Failed","Return Value: " + String(ll_RowCount) & + "~r~nWith error information:~r~n" + ls_Error) Else Messagebox("Failed","Return Value: "+String(ll_RowCount)) End If Else //Checks if any warning If len(ls_Error) > 0 Then MessageBox("Warning", "With warning information:~r~n" + ls_Error) Else MessageBox("Succeed", "Return Value: " + String(ll_RowCount) ) End If End If |
This example imports data from dw_1 into a DataWindow JSON string,
and then imports data in rows 2 through the end from the JSON string into
dw_2 (suppose dw_1 and dw_2 have the same column names):
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 |
long ll_RowCount string ls_DWJson, ls_Error ls_DWJson = dw_1.ExportJson(true) ll_RowCount = dw_2.ImportJsonByKey(ls_DWJson, ls_Error, Primary!, 2) //Checks if any error IF isnull(ll_RowCount) Then Messagebox("Error", "The method returns null") ElseIf ll_RowCount < 0 Then If len(ls_Error) > 0 Then Messagebox("Failed","Return Value: " + String(ll_RowCount) & + "~r~nWith error information:~r~n" + ls_Error) Else Messagebox("Failed","Return Value: "+String(ll_RowCount)) End If Else //Checks if any warning If len(ls_Error) > 0 Then MessageBox("Warning", "With warning information:~r~n" + ls_Error) Else MessageBox("Succeed", "Return Value: " + String(ll_RowCount) ) End If End If |
This example imports data (and state) in rows 1 through 10 from the
primary buffer of a DataWindow JSON string into the primary buffer of the
DataWindow:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
long ll_RowCount string ls_DWJson, ls_Error //DataWindow JSON ls_DWJson =… ll_RowCount = dw_1.ImportJsonByKey(ls_DWJson, ls_Error, Primary!, 1, 10) //Checks if any error IF isnull(ll_RowCount) Then Messagebox("Error", "The method returns null") ElseIf ll_RowCount < 0 Then If len(ls_Error) > 0 Then Messagebox("Failed","Return Value: " + String(ll_RowCount) & + "~r~nWith error information:~r~n" + ls_Error) Else Messagebox("Failed","Return Value: "+String(ll_RowCount)) End If Else //Checks if any warning If len(ls_Error) > 0 Then MessageBox("Warning", "With warning information:~r~n" + ls_Error) Else MessageBox("Succeed", "Return Value: " + String(ll_RowCount) ) End If End If |
See also