Virtual Table Properties

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See Also

Property Notes
allowupdate Allow updates: allowupdate=1
autosync Keep the local and remote cursor data in sync as changes are made multi-user: autosync=1
basetable Name of the base table to be used for insert, update and delete operations When combining data from multiple tables using a join you need to specify this and the updatefieldlist described below.
codec To handle character mapping between utf-8 and locale specific encoding for use with the VFP OLEDB driver, e.g. codec=windows-1252. See here for supported codepage values. From v7.1.
concatwhere To have the existing WHERE clause included in pagination: concatwhere=1
convertuint Set to 1 to correct the ODBC interpretation of BIT fields in MySQL: convertuint=1. From v6.0.
datasourceoptions Specify database specific options, e.g.: datasourceoptions=SQL_ATTR_PACKET_SIZE:102410. From v6.0.
dbtype The dbtype can be: lianja | mssql | mysql | oracle | postgres | vfp.

This makes connections faster as Lianja does not need to use heuristics to determine the remote database type.
There are various versions of mssql i.e. mssql2008, mssql2010, mssql2012, mssql2016.
Specifying mssql handles > 2008 and causes the engine to use OFFSET .. FETCH rather than use the OVER ... ORDER BY clause.

debug Enable debugging: debug=1
elapsedtime If enabled, the elapsed times for various VT operations are written to the debug_client.txt file. From v6.3.

Enable elapsedtime: elapsedtime=1

fetchasneeded Enable fetchasneeded: fetchasneeded=1
fetchsize Specify fetchsize: fetchsize=N
includeblobs Use this to cause varbinary fields to be saved to remote database servers in desktop Apps. Currently supports MySQL, MSSQL and Postgres. includeblobs=1. From v6.0.
includememos Use this to cause varchar fields to be saved to remote database servers in desktop Apps. Currently supports MySQL, MSSQL and Postgres. includememos=1. From v6.0.
keepalive Keep the ODBC connection alive when the request completes: keepalive=1
keyfieldlist Synonym of primarykey. Used to uniquely identify the row.
nodata Open without loading data: nodata=1. Note: this can also be set using object.setNamedParameter("nodata", "false"). The setNamedParameter() method is available on the Section, CursorAdapter and Cursor Framework Classes.
nosupportsoffset Enable nosupportsoffset: nosupportsoffset=1
pagination Enable pagination: pagination=1
password Connection password
postfixwhere Enable postfixwhere: postfixwhere=1. The WHERE clause will be applied to the resultset.
precision Specify precision for float fields (default is 2): precision=N
quotestring The quotestring property is used to handle CRUD statements containing embedded ' characters.
This should be set according to the requirements of the backend SQL engine.
e.g. to replace single quotes by two single quotes for MSSQL:
create virtualtable vtmssql_table properties "quotestring='';..." 

or to replace single quotes by \' for MSSQL:

create virtual table vtmysql_table properties "quotestring=\';..." 
rowid Enable rowid: rowid=1
supportslimit Specify that the backend database engine supports the LIMIT keyword: supportslimit=1
supportsoffset Specify that the backend database engine supports the OFFSET keyword: supportsoffset=1
translatecolumnname If this is true, column names with spaces are translated to use [] square bracket enclosures: translatecolumnname=true.
Note that when reading a MS SQL Server table that has spaces in the column names, these spaces are replaced with underscores so that they can be referenced in LianjaScript. Columns with underscores in their names should be excluded using the translatecolumnnames property (as below).
translatecolumnnames Specify the columns that should/should not be translated when the translatecolumnname property is true, e.g.


translatename Disable translation of remote table name (underscore to dot): translatename=false
translatequeryfunc Specify a function to be called to translate a native Lianja SQL WHERE condition for a target SQL database syntax. The function is called with two arguments: cWhereCondition, cDBtype. It should reside in the database container, e.g. : translatequeryfunc=yourFunc. From v6.0.
ttl Specify TTL: ttl=N. Used with keepalive=1, connections are released after the TTL has expired. Default is 30 which causes them to be released after 30 minutes.
updatefieldlist Comma-separated list of fields that can be inserted or updated. Prefix a field with a - to exclude it and use * to select all remaining fields. e.g. -custid,-custballance,*
username Connection username
wheretranslate Set this to 0 for queries to MS SQL Server with an OVER (PARTITION BY ...) clause and a WHERE clause, if the WHERE clause is wrongly translated/repositioned. From v8.0.
wheretype Type of fields used for where clauses: 1 = KeyFieldList, 2 = KeyFieldList and updatable fields, 3 = KeyFieldList and modified fields, 4 = KeyFieldList and comparison of time stamps.

A property that is unrecognized, e.g. mypar=myvalue, will be added as a "named parameter" and will be the default value to be substituted if no setNamedParameter("mypar", "myvalue") is specified. The setNamedParameter() method is available on the Section, CursorAdapter and Cursor Framework Classes.