The Leszynski naming convention (or LNC) is a variant of Hungarian notation popularized by consultant Stan Leszynski specifically for use with Microsoft Access development.[1] Although the naming convention is nowadays often used within the Microsoft Access community, and is the standard in Visual Basic programming, it is not widely used elsewhere.
The conventions are derived from an earlier set of conventions, the Leszynski/Reddick naming conventions, originally developed in 1992 by Greg Reddick. Eventually, Leszynski and Reddick had different ideas about how the conventions should be developed, and split into two separate sets of conventions, the other being the RVBA Conventions.
As in all Hungarian notations, it uses prefixes (called tags) to indicate the type of objects and database development fields. The general structure of Hungarian notation (named after Charles Simonyi's native country) is to break down object names into the following elements: [prefix(es)][tag]BaseName[Suffix/Qualifier] The tags are lower case and the object name is camel case. Spaces and underscores are not used.
Advantages[edit]Since the Leszynski naming convention is a special form of Hungarian notation the same general advantages also apply to the Leszynski convention.
The use of distinctive prefixes makes your database self-documenting; when you see frmSales in VBA code, you will know that it references a form, and when you see curSales you will know that it is a Currency variable. When selecting a query from a drop-down list, you will know that a query starting with qmak is a make-table query, while one starting with quni is a union query. This information will allow you to oid errors such as using the SetFocus method (a control method) with a field, or trying to open a table.
Disadvantages[edit] Since the Leszynski naming convention is a special form of Hungarian notation the same general disadvantages also apply to the Leszynski convention. Changes in database design may require wholesale renaming. For example, replacing a table with a query would involve either retaining the tbl name for the query, or going through the entire database replacing the tbl name with a query name. When transferring the database to a different DBMS, problems will arise if the target DBMS does not support CamelCase names. As every object of the same type starts with the same letter, it is not possible to nigate through the objects in a List box by typing the beginning letter. Elements[edit]The elements of the naming convention are described in the following table.
Component Description Example Prefix(es) A lowercase letter that adds extra information to the tag p for Public variable Tag A three-letter sequence indicating the object type tbl for table BaseName A word or two describing the object. If several words are used, each starts with a capital letter, and there are no spaces between them OutlookContacts – contacts imported from Outlook Suffix (RVBA), Qualifier (LNC) A word giving more specific information about an object ByDate – the data is sorted by date The Basic LNC Object Prefixes[edit] Object Tag Incomplete objects, backup objects, or objects that are under development _ or – (In some versions of Access, dashes sort to the beginning of the database object list.) Hidden system objects zh Displayed system objects zs Programmatically created temporary objects zt Backup copies of objects, for later copying or reuse zz The Basic LNC Variable Prefixes[edit] Variable Type Tag Local variable [no prefix] Local static variable s Module-level variable m Public variable in a form or report module p Public variable declared in the Declarations section of a standard module g The Basic LNC Database Object Tags[edit] Object Tag Class module cls Form frm Form (dialog) fdlg Form (menu) fmnu Form (message) fmsg Form (subform) fsub Macro mcr Module bas Module mod Query (any type) qry Query (append) qapp Query (crosstab) qxtb Query (data definition) qddl Query (delete) qdel Query (form filter) qflt Query (lookup) qlkp Query (make-table) qmak Query (select) qry (or qsel) Query (SQL pass-through) qspt Query (union) quni Query (update) qupd Report rpt Report (subreport) rsub Table tbl Middle Table trel Table (attached dBASE) tdbf Table (attached Excel) txls Table (attached FoxPro) tfox Table (attached Lotus) twks Table (attached ODBC) todb Table (attached Paradox) tpdx Table (attached SQL Server) tsql Table (attached text) ttxt Table (lookup) tlkp Pages pge The LNC Table Field Tags[edit] Object Tag Autonumber (random non-sequential) idn Autonumber (replication ID) idr Autonumber (sequential) ids Binary bin Byte byt Currency cur Date/Time dtm Double dbl Hyperlink hlk Integer int Long lng Memo mem OLE ole Single sng Text (character) chr Yes/No (Boolean) ysn The LNC Tags for VBA Variables[edit] Object Tag Boolean bln CommandBar cbr Control (generic; useful when cycling through controls on a form or report) ctl Currency cur Database dbs Double dbl Form frm Integer int Long lng QueryDef qdf Report rpt Single sng Snapshot snp String str Table tbl Type (user-defined) typ Variant var The LNC Tags for Form and Report Controls[edit] (may also be used in code referencing controls) Object Tag Attachment att Bound object frame frb Chart (graph) cht Check box chk Combo box cbo Command button cmd Custom control ocx Frame fra Hyperlink hlk Image img Label lbl Line lin List box lst Option button (Radio Button) opt Option group grp Page (on a Tab control) pge Page break brk Rectangle (shape) shp Subform/report sub Tab control tab Text box txt Toggle button tgl Button btn Unbound object frame fru Some Typical LNC Names for Database Objects, Controls and Variables[edit] Object/variable name LNC naming elements Description tblEmployees tag + base name A table of employee data qupdSales tag + base name A query that updates sales data fsubDayMax tag + base name + qualifier A subform that shows the maximum day intLines tag + base name An Integer variable to hold a value representing the number of lines in a Word table curSales tag + base name A Currency variable holding a Sales value pstrForm prefix + tag + base name A public String variable holding a form name zztblContacts prefix + tag + base name A backup Contacts table, for copying and filling with imported data References[edit]Part of this article is based on Helen Feddema's book, Expert One-on-One Microsoft Access Application Development, Wiley, ISBN 0-7645-5904-4.
^ "Naming Conventions for Microsoft Access (Archived Microsoft Access Content)". MSDN.Microsoft.com.[permanent dead link] External links[edit] Leszynski Naming Conventions for Microsoft Solution Developers LNC Renaming Add-in – A free Access add-in that automatically applies the LNC to an Access 2000, 2002 or 2003 database RVBA Conventions