I have an exam using SQLPlus and sometimes I don't remember the exact syntax of SQL statements, so I was wondering if there is any way to get some nice inline help from inside SQLPlus.
For instance, say I forgot how to use INSERT INTO, and I want some reminder like this:
INSERT INTO table-name (column-names)
VALUES (values)
Is this possible?
I tried HELP command but none of that seems to suits my needs.
I Googled it with no success.
No. SQL is a standardized language (at least ANSI SQL) and SQLPlus "just" uses that syntax, so it's not covered by internal help. Internal help lists only SQLPlus specific commands (ex. SET, CONNECT, SPOOL).
It is possible to workaround that in some way, but very limited. You can call dbms_metadata.get_ddl function for some existing object. Some of those DDLs could have statements you are intrested in. For example - you'd like to see select statement - then you could call dbms_metadata.get_ddl for some existing view:
select dbms_metadata.get_ddl('VIEW', 'USER_TABLES', 'SYS')
from dual;
Be aware - it works only for Oracle 11G and lower, in the newest one SYS objects are not accessible in that way (I'm not sure about Oracle 12.1).
The more interesting are tiggers, procedures, functions, and packages. You cannot use dbms_metadata to get DDLs of packages owned by SYS, but maybe you can connect to some sample schemas like HR (Human Resources), AD (Academic), SH (Sales History).
In HR schema there is stored procedure ADD_JOB_HISTORY, which has inside insert statement, so it looks like that:
select dbms_metadata.get_ddl('PROCEDURE', 'ADD_JOB_HISTORY')
from dual;
CREATE OR REPLACE EDITIONABLE PROCEDURE "HR"."ADD_JOB_HISTORY"
( p_emp_id job_history.employee_id%type
, p_start_date job_history.start_date%type
, p_end_date job_history.end_date%type
, p_job_id job_history.job_id%type
, p_department_id job_history.department_id%type
)
IS
BEGIN
INSERT INTO job_history (employee_id, start_date, end_date,
job_id, department_id)
VALUES(p_emp_id, p_start_date, p_end_date, p_job_id, p_department_id);
END add_job_history;
There are better ways and better tools to achieve your goal - see below.
Are you allowed to use SQL Developer instead of SQLPlus? SQL Developer has nice feature to drag-and-drop table icon into worksheet, then you will be nicely prompted to choose what kind of example statement you are looking for (SELECT, INSERT, UPDATE etc.) - after choosing one you will get sample statement.
But the best way is just open in browser Database SQL Language Reference:
https://docs.oracle.com/database/121/SQLRF/toc.htm
Related
Is there a way to use Firedac to handle conditional scenarios.
Master Table has a column called INVOICESCOUNT.
When an invoice is deleted successfully, then the INVOICESCOUNT is decreased.
For example, a SQL psuedo-code statement like this:
Delete From Invoices where INVOICE=500;
Update Customers SET INVOICECOUNT=INVOICECOUNT-1 WHERE Customer=1 (if prior statement returns 1 affected row);
I need it to be embedded within the same SQL statement instead of having the Delphi source code handling executing the 2 statements separately, after the first FDQuery returns a successful execution.
Thanks for any advice.
That's fine ?
I understood, lack of attention from me, in this case I could use the information from the DBMS itself, an example, if the DBMS is SQL server.
Delete From Invoices where INVOICE=500
IF ##ROWCOUNT=1
begin
Update Customers SET INVOICECOUNT=INVOICECOUNT-1
WHERE Customer=1
end.
If your DBMS doesn't allow it, I recommend you to use a stored procedure.
Windows 10, Access 2016
I am moving a very small database (14 tables and 40-50 stored procedures) from SQL Server to Access. I have tried to recreate the stored procedures from code using an OLEDB command object. This is a sample of a CommandText…
CREATE PROCEDURE DeleteOrderDetailByOrderID
([#ID] int)
AS
DELETE FROM OrderDetails
WHERE (OrderID = #ID);
I get an error message that the Data Type of #ID is incorrect. It is not. When I remove the brackets from #ID all is forgiven and the code runs. However, Access strips the # from #ID in the parameter section (not in the Where clause). I have had to go into Access and manually correct this. I do not like the idea of going through almost 5000 lines of code to correct parameter names in my program. I thought I could use the direct approach by pasting the SQL directly into Access but I get an error with this route saying syntax error in CREATE TABLE and it highlights the word PROCEDURE. This leads me to believe that you cannot use CREATE PROCEDURE directly in Access. Is this true? Is there another approach that I am missing?
You are missing, that T-SQL of SQL Server is not Access SQL.
Access has UDFs - user defined functions - that can be used in queries also, but that is VBA code.
If you just need a single-user file based database to hold your data, you may get away with the SQL Server Compact Edition which supports a subset of T-SQL.
I was using UniDac for a long time now and decided to move on to FireDac as it has good Asynch methods after moving on i saw that none of my data editing works anymore it gives me an error:
[FireDAC][Phys]-330. Cannot generate update query. Update table undefined.
What I am trying to do here is i have a TFDStoredProc component who gets all the data from the database and lets me edit it, with unidac I could easily edit the data without any problem like this:
StoredProc.Edit;
StoredProcCreatedID.Value := SomeValue;
StoredProc.Post;
and it worked, but with AnyDac it doesn't, I tried specifying manually the UpdateTable which leads to another problem:
[FireDAC][Phys][ODBC][Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'CreatedID'.
I am using Microsoft SQL Server 2012 FireDac 8.0 and stored procedures for getting back results any ideas?
P.S.
The query looks like this
SELECT
CreatedBy as CreatedID,
usr.UserName as CreatedBy
FROM
Sales
LEFT JOIN
Users usr ON usr.ID = Sales.CreatedBy
it looks like the FireDac update builder doesn't recognize the aliases on the fields, any help would be appreciated.
Well i figured out what was the issue, it seems that if you specify a alias in the query for a field the Origin property will be set to the alias and not the real field i downloaded CNPack a must have for a delphi developer also its free, ran the component selector and changed all my aliased fields to their real fields and it works, but this is still a big issue in FireDac component because it doesnt recognize the aliased fields, lets hope it will be fixed in the future as to specify for every query what table it should update and what fields that just allot of work if you are migrating from a big project in my case 220+ stored procedures.
I am trying to use Macros in FireDAC to Preprocess my SQL Queries. I have a TADQuery object on a Data Module with the SQL set to something like:
Select * from MyTable
join OtherTable on MyTable.Key = OtherTable.Key
&Where
Then in my code I do this:
WhereClause = 'stuff based on my form';
Query.MacroByName('Where').AsRaw := WhereClause;
Query.Open;
This has worked great for complicated queries because it lets me make sure my fields and join conditions are correct using the SQL Property editor.
My problem is when the SQL statements ends up invalid because of my where clause. Is there any way to see the SQL after pre-processing that is going to be executed? Right now I am catching the FireDac errors and showing the SQL that is on EADDBEngineException object. However that is still showing my original SQL with the macros. If I can't get to it after the error happens is there anyway to force the Macro replacement to take place so I can look at the SQL in the debugger to help me see what is wrong.
If it matters I am connecting to a MS Access database with the goal of moving to SQL Server in the near future.
Apart from using Text property, to monitor what SQL is actually going to the database engine, consider using the "FDMonitor" FireDAC utility. According to the DokWiki pages (below):
drop a TFDMoniRemoteClientLink component on your form,
Set its Tracing property to True,
Add the MonitorBy=Xxx connection definition parameter to your existing FDConnection component. You can do this in the IDE object inspector, by selecting your FDConnection component, expanding the Params property, and setting MonitorBy to mbRemote.
Note that the TFDMoniXxxxClientLink should come before TFDConnection in the data module or form creation order, so adjust this by right clicking on the form or data module, then Creation Order, and moving the TFDMoni.. component above the FDConnection.
Also, it's helpful in the options of the TFDMoniXxxxClientLink, to disable most of the events being recorded, otherwise all the data returned is also shown in the FireDAC monitor. Expand the EventKinds property, and turn all the event kinds off, except for perhaps ekConnConnect, ekConnPrepare, and ekCmdExecute.
Then open the FireDAC Monitor from the IDE, (Tools > FireDAC Monitor). Start your app only once the monitor is running. Double click on a trace event (in the Trace Output tab), and you will see the actual SQL sent to the database in the bottom pane.
It also seems likely that adding the EventType of ekConnPrepare as mentioned above, would show you when the query's Prepare is called, but I haven't played enough with it say for sure.
Please see the following pages on the DocWiki for more information:
Overview: FDMonitor
How to: Tracing and Monitoring (FireDAC)
Other FireDAC utilities: Utilities (FireDAC)
(Just to remove this question from list of unanswered questions)
From comments:
Well, I've roughly checked what's happening there and I'm still not
sure if calling Prepare (which is useless for you as I get) is the
minimal requirement to trigger that preprocessing. Though, the
preprocessed SQL, the one which is sent to the DBMS you can access
through the Text property (quite uncommon name for such property). – TLama Feb
21 '14 at 8:18
I would like to create a generic logging solution for my stored procedures, allowing me to log the values of input parameters. Currently I am doing this more or less by hand and I am very unhappy with this approach. Ideally, I would like to say something like the following:
"given my spid, what are my input parameters and their values?"
This is the same information exposed to me when I run SQL Profiler -- the stored procedure's name, all input params and all input VALUES are listed for me. How can I get my hands on these values from within a stored procedure?
Thanks;
Duncan
That is going to be difficult to do within a stored procedure. SQL profiler runs under a different SPID and runs a statement like this to capture the other users statements:
DECLARE #handle VARBINARY(64)
SELECT #handle = sql_handle from sys.sysprocesses where spid = #SPID
SELECT text FROM sys.dm_exec_sql_text(#handle)
The problem is if you run this in a stored proc for the current SPID all your going to get back is the statement above. I don't believe SQL server provides a T-SQL construct to execute a batch under a different SPID. I suppose you could write a .Net dll stored procedure that executes a batch on a different connection. to do that sort of thing but it may be more trouble than it's worth.