Basics SQL in Control
The database functions enable you to quickly carry out value queries on data points and elements. It is also possible in WinCC OA to create value queries with the SQL-Panel (for more information, see also the chapter Basics SQL-Panel).
WinCC OA provides functions that allow detailed querying of individual parts of data points. The results returned as data fields can be filtered and processed, for example, sort, add, search for minimum and others.
Keywords for data points
Data points in WinCC OA show the following structure:
System:datapoint.element:config.detail.attribute
The names for the individual levels (identifiers) are in part freely selectable in WinCC OA. On account of the freedom of naming, a unique assignment between a level and a name is not possible. For this reason, there are predefined keywords for addressing the individual levels:
Table: Keywords for WinCC OA
| _SYS | system level |
| _DP | data point level |
| _EL | element level |
| _KF | config level |
| _DT | detail level |
| _AT | attribute level |
| _DPT | data point type |
| _ALIAS | alias (query only via WHERE keyword supported) |
| _COMMENT | comment (from Resources::ParamLang - the language of the comment cannot be selected; query only via WHERE keyword supported) |
| _ELC | element type as Control constant (DPEL_xxx) |
| _LEAF | selects only leaf elements |
For general reasons, there are also keywords for the first three levels in this table. However, the selection in these levels should already be made at wildcard level. Although the address "*:*;" is theoretically possible (simply everything in all systems) it is not advisable to use it. The evaluation of these keywords always relates to the entire line (that is to the FROM part of the query).
| Chapter | Description |
| Basics SQL in Control | Introduction SQL in Control |
| Control functions for SQL | Links to the functions that are needed for querying the WinCC OA database |
| Data management | Data management in WinCC OA |
| Wildcards | Explaining Wildcards and examples |
| Wildcards in the element identifier | Using wildcards for data point elements |
| Queries | Structure of the Query-commands and examples |
| SQL keywords | Different query-commands and functionality with SQL-queries (for example MIN, MAX, TIMERANGE) |
| Basics SQL-Panel | As from WinCC OA version 2.11.1, the SQL-Panel simplifies the process of creating value queries |
| Examples | Examples for SQL-queries with current statements and Control functions |
| Tips and tricks | Hints for using SQL in CONTROL |
| Glossary | Important concepts and shortcuts |
| Summary and continuation to other chapters connected with SQL in Control | Links to other chapters |
