I would like to what's the command to dump only columns names, not data type. And also is it possible we can search in data? Like fetch the column data having #gmail.com or word 'admin.
--columns option can be used to enumerate the columns
--where=constraint option can be used to search for specific data (similar to SQL's where clause)
Ex: --where="mail='abc#gmail.com'"
mail is the column name and abc#gmail.com is the keyword to be searched
Refer to Usage Section here
Related
Long story short, I can't use pivot for this task due to the long elements that I need to include in the columns. Although I tried to create a Classic Report based on function in Oracle Apex. The query it's generated correctly but it's not working in the Classic Report.
A general hint first: Output your variable l_sql to your console using dbms_output.put_line or use some kind of debugging table where you can insert it into. Also be careful about the data type of that variable. If you need to expand the SQL you can reach a point where you need to use a CLOB variable instead of varchar2.
You will need to supply table structures and test data if you like to have your problem analyzed completely, therefore I will at first give you some general explanations:
Use Generic Column Names is ok if you have a permanent, unchangable amount of columns. But if the order of your columns or even the amount can change, then this is a bad idea, as your page will show an error if your query results in more columns than Generic Column Count
Option 1: Use column aliases in your query
Enhance your PL/SQL Function Body returning SQL Query in a way that it outputs verbose display names, like this:
return 'select 1 as "Your verbose column name", 2 as "Column #2", 3 as "Column #3" from dual';
That looks like this:
It has the disadvantage that the column names also appear in this way in the designer and APEX will only update these column names if you re-validate the function. You will have a hard time to reference a column with the internal name of Your verbose column name in a process code or dynamic action.
However it still works, even if you change the column names without telling APEX, for example by externalizing the PL/SQL Function Body into a real function.
Option 2: Use custom column headings
A little bit hidden, but there is also the option of completely custom column headings. It is almost at the end of the attributes page of your report region.
Here you can also supply a function that returns your column names. Be careful that this function is not supposed to return an SQL query that itself returns column names, but instead return column names seperated by a colon.
With this method, it is easier to identify and reference your columns in the designer:
Option 3: Both of it
Turn off Generic Column Names, let your query return column names that can be easily identified and referenced, and use the custom column headings function return verbose names for your users.
My personal opinion
Im using the 3rd option in a production application where people can change the amount and order of columns using shuttle items on the report page themselves. It took some time, but now it works like a charm, like some dynamic PIVOT without PIVOT.
I want to write same query for multiple files. Is this possible to write dynamic query in U-SQL or is there any way to eliminate re-writing of same piece of code like
Select count(*) as cnt from #table1;
Select count(*) as cnt from #table2;
can be replaced to
Select count(*) as cnt from #dynamic
where #dynamic = table1, table2
(Azure Data Lake team here)
Your question mentions reading from files, but your example shows tables. If you do really do want to read from files, the EXTRACT statement supports "File Sets" that allow a single EXTRACT statement to read multiple files that are specified by a pattern
#data =
EXTRACT name string,
age int,
FROM "/input/{*}.csv"
USING Extractors.Csv();
Sometimes, the data needs to include the filename the data came frome, so you can specify it like this:
#data =
EXTRACT name string,
age int,
basefilename string
FROM "/input/{basefilename}.csv"
USING Extractors.Csv();
I use a custom CSV extractor that matches columns to values using the first row in the CSV file.
Here is the Gist to be added as in code behind or as a custom assembly: https://gist.github.com/serri588/ff9e3047d8341398df4aea7557f0a82c
I made it because I have a list of files that have a similar structure, but slightly different columns. The standard CSV extractor is not well suited to this task. Write your EXTRACT with all the possible column names you want to pull and it will fill those values and ignore the rest.
For example:
Table_1 has columns A, B, and C.
Table_2 has columns A, C, and D.
I want A, B, and C so my extract would be
EXTRACT
A string,
B string,
C string
FROM "Table_{*}.csv"
USING new yourNamespace.CSVExtractor();
Table 1 will populate all three columns, while Table 2 will populate A and C, ignoring D.
U-SQL does not provide a dynamic execution mode per se, but it is adding some features that can help with some of the dynamic scenarios.
Today, you have to provide the exact schema for table type parameters for TVFs/SPs, however, we are working on a feature that will give you flexible schema parameters that will make it possible to write a TVF/SP that can be applied to any table shape (as long as your queries do not have a dependency on the shape).
Until this capability becomes available, the suggestions are:
If you know what the possible schemas are: Generate a TVF/SP for each possible schema and call it accordingly.
Use any of the SDKs (C#, PowerShell, Java, Python, node.js) to code-gen the script based on the schema information (assuming you are applying it to an object from which you can get schema information and not just a rowset expression).
I have:
<cfspreadsheet action="read" src="#Trim(PathToExcelFile)#" query="Data">
How do I count the total column in my "Data" query using ColdFusion Query of Query? I need to count whether my users has used the corrent excel file format before inserting into my DB.
I'm using Oracle 11g and I can not do:
Select * From Data Where rownum < 2
If I can do that then I can create an array and count the columns but running that script using results in error. The error saying that there is no column name Rownum. Oracle does not allow me to use select top 1.
I don't want to loop over 5000+ record to just count the total column of one row. I appreciate any help, thank you
ColdFusion adds a few additional variables to it's query results. One of them is named `columnList' and contains a comma-separated list of the query columns that were returned.
From the documentation here
From that you should be able to count the number of columns easily. #listlen(Data.columnList)# as one example.
I want to create a MVCCKey with a timestamp and pretty value I know. But I realize a roachpb.key is not very straightforward; is there some prefix/suffix involved? Is the database name is also encoded in roachpb.key?
Can anyone please tell me how a MVCCKey is formed? What information does it have? In the documentation, it just says that it looks like /table/primary/key/column.
An engine.MVCCKey combines a regular key with a timestamp. MVCCKeys are encoded into byte strings for use as RockDB keys (RocksDB is configured with a custom comparator so MVCCKeys are sorted correctly even though the timestamp uses a variable-width encoding).
Regular keys are byte strings of type roachpb.Key. For ordinary data records, the keys are constructed from table, column, and index IDs, along with the values of indexed columns. (The database ID is not included here; the database to which a table belongs can be found in the system.descriptors table)
The function keys.PrettyPrint can convert a roachpb.Key to a human-readable form.
I have multiple data sets that drive the Pentaho report. The data is derived from a handful of stored procedures. I need to access multiple data sources within the report without using sub reports and I believe the best solution is to create open formulas. The SINGLEVALUEQUERY I believe will only return the first column or row. I need to return multiple columns.
As an example here my stored procedure which is named HEADER in Pentaho (CALL Stored_procedure_test (2014, HEADER)), returns 3 values - HEADER_1, HEADER_2, HEADER_3. I'm uncertain of the correct syntax to return all three values for the open formula. Below is what I tried but was unsuccessful.
=MULTIVALUEQUERY("HEADER";?;?)
The second parameter denotes the column that contains the result.
If you dont give a column name here, the reporting engine will simply take the first column of the result. In the case of the MULTIVALUEQUERY function, the various values of the result set are then aggregated into a array of values that is suitable to be passed into a multi-select parameter or to be used in a IN clause in a SQL data-factory.
For more details see https://www.on-reporting.com/blog/using-queries-in-formulas-in-pentaho/