History Table Format
- Last UpdatedMar 10, 2025
- 1 minute read
The History table presents acquired plant data in a historical format, which is shown as follows:
|
DateTime |
TagName |
Value |
vValue |
Quality |
QualityDetail |
(continued...) |
|
2017-02-17 15:40:01.0000000 |
Temp1 |
78 |
78 |
0 |
192 |
(continued...) |
|
2017-02-17 15:40:31.0000000 |
Temp2 |
79 |
79 |
0 |
192 |
(continued...) |
|
2017-02-17 15:41:01.0000000 |
Temp3 |
77 |
77 |
0 |
192 |
(continued...) |
|
2017-02-17 15:41:31.0000000 |
Temp4 |
80 |
80 |
0 |
192 |
(continued...) |
|
2017-02-17 15:42:01.0000000 |
Temp1 |
77 |
77 |
0 |
192 |
(continued...) |
|
2017-02-17 15:42:31.0000000 |
Temp2 |
78 |
78 |
0 |
192 |
(continued...) |
|
2017-02-17 15:43:01.0000000 |
Temp3 |
76 |
76 |
0 |
192 |
(continued...) |
|
2017-02-17 15:43:31.0000000 |
Temp4 |
79 |
79 |
0 |
192 |
(continued...) |
|
2017-02-17 15:44:01.0000000 |
Temp1 |
76 |
76 |
0 |
192 |
(continued...) |
|
2017-02-17 15:44:31.0000000 |
Temp2 |
77 |
77 |
0 |
192 |
(continued...) |
|
2017-02-17 15:45:01.0000000 |
Temp3 |
78 |
78 |
0 |
192 |
(continued...) |
|
2017-02-17 15:45:31.0000000 |
Temp4 |
80 |
80 |
0 |
192 |
(continued...) |
There is one row for a single tag's value for a particular timestamp.
Note: The AnalogHistory, DiscreteHistory, and StringHistory tables are provided for backward compatibility and can only accept tagnames in the SELECT statement that are of the same type; that is, you cannot mix the tag types in the query without doing a UNION. The History table, however, can accommodate a mixture of tag types and should be used instead of the AnalogHistory, DiscreteHistory, or StringHistory tables. The Value column returns a float value for analog and discrete tags, a NULL for string tags. The vValue column returns a sql_variant for all tag types.