In my tjavaFlex Component Schema, I have set a default value("00") for a column ("RecordCode") in the "Default" column. I'm expecting that this value will take effect when a value is not assigned explicitly to the ("RecordCode") column. But it does not. When does the default value take effect?
Checking the talend documentation
"At present, only tFileInputDelimited, tFileInputExcel, and tFixedFlowInput support default values in the schema."
Not sure they have planned to add support for this in the coming years...
Related
When we use Mybatis , in <select> ...</select> statment I know we need set jdbcType beacuse the IN variable maybe null, but when I see the document of Mybatis, I found jdbcType in <result>...</result> under ResultMap. the document of the
jdbcTpe in <result>...</result> was:
... The JDBC type is only required for nullable columns upon insert, update or delete. This is a JDBC requirement, not a MyBatis one. So even if you were coding JDBC directly, you'd need to specify this type – but only for nullable values.
the bold word say only required for nullable columns upon insert, update or delete.
BUT,the element of result is used in select neither insert, update or delete.
so ,is it necessary use jdbcType in <result>...</result> ?
Most of the time, no. Why? Read on.
If you want to use a null as a JDBC parameter value you need to specify the jdbcType. That's a restriction of the JDBC specification you can't avoid. Therefore, if there's even a remote possibility a JDBC parameter could have a null value, then yes, specify it.
This does not apply to parameters preprocessed by MyBatis inside MyBatis tags, like the ones you use in the "test" attribute of the < if > tag. Those ones are not JDBC parameters.
Now, for the columns you read. These are the ones you are interested on. The thing is most of the time you don't need them. MyBatis will pick the right JDBC type for you. Well... this has been the case for me 99.999% of the time.
What about the other 0.001%? For some exotic column types -- that you rarely use -- MyBatis may pick the wrong JDBC type for you. The designers of MyBatis thought about this case, and give you the chance of overriding it. I think I remember an XML type database column that MyBatis was unsuccessfully trying to read as a VARCHAR, but I don't remember which database.
Bottom line, don't use it when reading columns, unless MyBatis reads exotic data type columns (XML, UUID, POINT, etc.) the wrong way.
I'm importing data from MS Excel to MySQL Database using Talend ETL Tool, few columns might not have data in this case i need to consider default value.
how to give default value in talend ETL tool?
The simple way should look like this:row1.yourField == null ? "defaultValue" : row1.yourFieldYou'll have to do this for each concerned field with the appropriate default values.
Default value on database side will not work for the fields which participate to the query, so you have to transform the value on client side.
Hope this helps.
TRF
You can achieve this by writing an expression in the Tmap component of Talend to map the nulls with some default value.
row1.column=null ? “Default value” : row1.column
This needs to be done for every field wherein the mapping with default value is needed.
You may also refer the below link for a similar issue:
https://www.talendforge.org/forum/viewtopic.php?id=33623
I have this simple flow in Talend DI 6 (simplified for posting on SO):
The last step crashes with a NullPointerException, because missing XML attributes are returned as null.
Is there a way to get empty string values instead of nulls?
For now I'm using a tReplace step to remove nulls as a work-around, but it's tedious and adds to the cost of maintenance by creating one more place where the list of attributes needs to be maintained.
In Talend DI 5.6.2 it is possible to add default data values to the schema. The column in the schema is called "Default". If you expect strings, you can set an empty string, which is set if the column value is null:
Talend schema view with Default column
Works also for other data types. Talend DI 6 should still be able to do this, although the field might be renamed.
I need to pass value from Tpostgressql to context variable,so that context variable value can be used in other components
The query used in tpostgres is :
select max(started_on) started_on from etl_log
I have created a context variable started_on_date (date datatype)
In the Tjavarow :-
context.started_on_date =row1.started_on
But it throws
error created_on variable cannot be resolved or is not a field
Have you defined the schema in the tPostrgesqlInput component ? If not, that needs to be done first. Afterward, synchronize the schema of the tJavaRow. You can use the Java row's code generation feature, if appropriate .
Question / if you want to do row-based processing in the same job, there is likely no need to put the started date in the context.
If you want to do non-row based processing, you can used the tJavaRow component to put the value in the globalMap. This assumes there is only one row of data or that you only care about the last row. Then, you can use that value in other components which are not processing a flow (rows). tJava is an example of that.
I am using Red-Gate Data Compare to synchronize two databases, lets call them DBSource and DBDestination. DBDestination has a table, TableA which has a field which has a not null constraint. TableA within DBSource has the same structure, apart from this new field.
When I synchronize using the Data Compare tool, it fails due to this particular not null field, since there's no object map I can set up for it.
I wanted to know if there is a way of setting a default on the tool, since I can't alter the schema of the destination table and the file is quite large to edit?
The best way to handle this is to alter the column in the database and put a default value on it. There isn't anything you can do in the SQL Data Compare settings to make it replace illegal NULL data with a default value.