On Mon, 17 Dec 2012, LacaK wrote:
michael.vancann...@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)
Ah, that was not clear to me :-)
But why the SCHEMA_TABLE_NAME ? It's redundant information, as the
information is present in SCHEMA_NAME and TABLE_NAME anyway ?
If you need the schema name, why not just access the SCHEMA_NAME field ?
A different story is the GetTableNames call, which will - presumably - use
the above information.
There I think some extra options are needed:
TSchemaOption = (soPrependSchemaName,soIncludeSystemObjects);
TSchemaOptions = set of TSchemaOption;
Procedure GetTableNames(List : TStrings; Options : TSchemaOptions = []);
I am not interested in schema information, but I can imagine some people are
(the original poster, obviously). The above caters for everyone and keeps
backwards compatibility.
Michael.
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