[fpc-pascal] GetTableNames in TSQLConnection / Postgresql

[LacaK]

michael.vancanneyt at wisa.be  wrote / napísal(a):
>
>
> On Mon, 17 Dec 2012, LacaK wrote:
>
>>>>> 2)  The simple way to get the schemas would be to simply 'select 
>>>>> ... schemaname||'.'||relname as table_name ... from 
>>>>> pg_stat_user_tables. This would be a change ONLY to the sql in 
>>>>> pqconnection.  (If worst comes to worst, I dare say could create 
>>>>> my own pqconnection derivative with this change.)
>>>> Hm, if you want get also schema_name then you should use this 
>>>> approach:
>>>> sqlquery1.SchemaType:=stTables;
>>>> sqlquery1.Open;
>>>> and in loop fill TStrings using 
>>>> sqlquery1.FieldByName('schema_name')+'.'+sqlquery1.FieldByName('table_name') 
>>>
>>> At present, the schema isn't read into the query (so we have to 
>>> change the db connection), and the above code would have to be put 
>>> into TSQLConnecion, where (1) it would only apply to stTables, and 
>>> (2) would not work if any database species did not return the 
>>> schema.  Probably to do this it would be necessary to be able to 
>>> select multiple fields in the AReturnField of GetDBInfo, all of 
>>> which would be far more complicated than what I suggested as a 
>>> "simple" solution!
>> *Yes it will be more complicated.
>>
>> I did short comparasion in Delphi and in case of BDE table names are 
>> returned as "schema.table" in case of ADO,DBX only "table" without 
>> schema is returned. So again inconsistency between various DB client 
>> technologies.
>
> IMHO all the more reason to use 2 different fields, and keep table in 
> 1 field.
>
>> If others agree, IMO we can do it like this:
>> 1. use PG specific system view query, where we add SCHEMA_TABLE_NAME 
>> column (other columns like SCHEMA_NAME, TABLE_NAME, TABLE_TYPE etc 
>> remains) which will be as you suggested: schemaname||'.'||relname
>
> I would use 2 separate fields. This way the table field always only 
> contains
> the table. People interested in the schema, can read the schema field.
Yes. May be, that I was not clear. My suggestion was 3+ fields in query:
SCHEMA_NAME, TABLE_NAME, SCHEMA_TABLE_NAME (SCHEMA_NAME || '.' || 
TABLE_NAME)

But original question AFAIU was about: what should GetTableNames return 
(schema query can return multiple columns, but what column use when fill 
list of table names)?
GetTableNames return list of table names into TStrings.
Now only TABLE_NAME is returned. John requested, that also schema name 
should be prefixed (if there is any)

-Laco.

>
> It's easier to concatenate 2 fields than to separate out 2 parts of a 
> field,
> doubly so if you don't know whether the 2 parts are there or not.
>
> Michael.
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