ajDBGetLOB function
Description
The ajDBGetLOB function retrieves a file from a Large Object column in a database table satisfying the criteria specified in filter_condition. Please take note that to run this function from Excel, you need to set up the Data Source Connection in ##ExternalResources.
Syntax
ajDBGetLOB( table_name, lob_info, filter_type, filter_condition, table_schema, [data_source_id], [run_condition], [run_by_function_point_only] )
Argument Name | Argument Type | Description |
---|---|---|
table_name (required) | String | The name of the table that stores the file. |
lob_info (required) | Range / Array | The range that contains the LOB field information. Refer to the LOB Info snippet to see how you can use this snippet to define the required fields. |
filter_type (required) | Double | The type of filter. The value can be 0, 1 or 2. |
filter_condition (required) | Range / Array | The range that defines the filter condition. filter_type = 0. The range defines the WHERE clause of a SQL statement. The range will be concatenated into a single string. For example, Name = 'peter' and class = 'B'. filter_type = 1. The range defines the filter condition in the Kendo grid style. Click Insert Snippet\Filter Condition (Filter Type 1) to add the preset required format. filter_type =2. The range defines a filter condition similar to the format used in MS Query. Click Insert Snippet\Filter Condition (Filter Type 2) to add the preset required format. Refer to the Filter Condition snippet to see how you can use this snippet to define the required fields for filter type 1, 2. |
table_schema (required) | Range / Array | Specifies the Excel range that defines the DB Schema. The key column(s) must be included in the Column_headers and Data. Otherwise, an error will be raised. |
data_source_id (optional) | String | The data source shall be used in this database operation. It shall be defined in ##ExternalResources worksheet. The default value is "primary". |
run_condition (optional) | Boolean | The function will run when the value is TRUE. Otherwise, it will not run. The default value is TRUE. |
run_by_function_point_only (optional) | Boolean | If it equals FALSE, the function can be executed through ‘Excel Calculation’ (can be either Automatic or Manual, Calculate Now or Calculate Sheet) or Preview Function Point. If it equals TRUE, the function can be executed with Preview Function Point (AlchemyJ ribbon / Preview Function Point) only. The default value is TRUE. |
The function will return:
1) Return Value: Number of affected records.
2) Return Type: Single Value / Multiple values (array formula).
Example
In this example, we will use the following table. The table name is tb_supporting_doc. It has 5 columns and 2 rows.
Download the file from the CONTENT field of the record with ID 1001. 1 record is affected. Since the LOB File Name is provided (picture.png), it overrides the value defined in the LOB File Name Field column.
If the folder path does not exist, it will be created automatically.
Click here to download the use case workbooks for further reference.
Notes
- The column that stores the file should be a LOB (Large Object) or a CLOB (Character Large Object).
- Only one file can be stored in a LOB field.
- If the filter condition does not match anything, the function will return 0.
- It is expected that the filter condition should match one record only. If more than one record is found, the file in the last record will be saved.
- If the file exists, it will be overwritten.
- For more details about filter options, you can refer to the ajDBReadRecord function.
Error Scenarios
It will return #VALUE! when missing any required parameter or mismatch parameter type. Besides, system will raise error for below scenario(s).
Error Scenario |
---|
DB connection error. |
Table name is empty. |
Filter type is invalid, it must be 0, 1, or 2. |
Data name in filter condition does not exist in the provided table schema. |
Total number of filter condition columns is not even number. |
Data name in filter condition is empty. |
Operator in filter condition is empty. |
Invalid operator value in filter condition. |
And/Or in filter condition is invalid. |
Content in filter condition range does not meet the expected format of specified filter type. |
Either filter condition or table schema must be provided. |
Table name does not exist in provided DB Schema. |
The table schema columns are invalid. |
The table schema range does not include a header or a row of data. |
The provided column header cannot be found in the specified table schema range. |
No Key order value defined in DB Schema. |
Column header is not a single row range or a single column range. |
Invalid filter condition, it can only be 0, 1 or 2. |
LOB info is empty. |
LOB content field in LOB info is empty. |
LOB content folder in LOB info is empty. |
LOB file name in LOB info is empty. |
LOB content folder in lob info not found. |
LOB info range is invalid. |
LOB field name cannot be found in the database. |
LOB character set field cannot be found in the database. |
Failed to create LOB Content Folder. |
Upload file is not found. |
CLOB defined in DB Schema but CLOB character set field in LOB info is empty. |
CLOB defined in DB Schema but CLOB character set in LOB info is empty. |