From b7ba65c3c1e7e2639c09584384f5a686dffdc576 Mon Sep 17 00:00:00 2001 From: Steven Li Date: Fri, 22 Nov 2019 18:47:04 -0800 Subject: [PATCH] Partial fix of #761, corrected bad characters --- .../tdenginedocs-en/super-table/index.html | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/documentation/tdenginedocs-en/super-table/index.html b/documentation/tdenginedocs-en/super-table/index.html index 3ebb0775b5..21e7669a19 100644 --- a/documentation/tdenginedocs-en/super-table/index.html +++ b/documentation/tdenginedocs-en/super-table/index.html @@ -6,9 +6,9 @@

Like a table, you can create, show, delete and describe STables. Most query operations on tables can be applied to STable too, including the aggregation and selector functions. For queries on a STable, if no tags filter, the operations are applied to all the tables created via this STable. If there is a tag filter, the operations are applied only to a subset of the tables which satisfy the tag filter conditions. It will be very convenient to use tags to put devices into different groups for aggregation.

Create a STable

Similiar to creating a standard table, syntax is:

-
CREATE TABLE <stable_name> (<field_name> TIMESTAMP, field_name1 field_type,…) TAGS(tag_name tag_type, …)
+
CREATE TABLE <stable_name> (<field_name> TIMESTAMP, field_name1 field_type, ...) TAGS(tag_name tag_type, ...)

New keyword "tags" is introduced, where tag_name is the tag name, and tag_type is the associated data type.

-

Note：

+

Note:

  1. The bytes of all tags together shall be less than 512
  2. Tag's data type can not be time stamp or nchar
    3. @@ -30,12 +30,12 @@ tags (location binary(20), type int) create table t4 using thermometer tags ('shanghai', 20); create table t5 using thermometer tags ('new york', 10);

    Aggregate Tables via STable

    -

    You can group a set of tables together by specifying the tags filter condition, then apply the aggregation operations. The result set can be grouped and ordered based on tag value. Syntax is：

    -
    SELECT function<field_name>,… 
+
    You can group a set of tables together by specifying the tags filter condition, then apply the aggregation operations. The result set can be grouped and ordered based on tag value. Syntax is:
    
+
    SELECT function<field_name>, ... 
  FROM <stable_name> 
- WHERE <tag_name> <[=|<=|>=|<>] values..> ([AND|OR] …)
+ WHERE <tag_name> <[=|<=|>=|<>] values..> ([AND|OR] ...
  INTERVAL (<time range>)
- GROUP BY <tag_name>, <tag_name>…
+ GROUP BY <tag_name>, <tag_name> ... 
  ORDER BY <tag_name> <asc|desc>
  SLIMIT <group_limit>
  SOFFSET <group_offset>
@@ -75,9 +75,9 @@ INTERVAL(10M)
    
 
    DROP TABLE <stable_name>
    
 
    To delete a STable, all the tables created via this STable shall be deleted first, otherwise, it will fail.
    
 
    List the Associated Tables of a STable
    
-
    SELECT TBNAME,[TAG_NAME,…] FROM <stable_name> WHERE <tag_name> <[=|=<|>=|<>] values..> ([AND|OR] …)
    
+
    SELECT TBNAME,[TAG_NAME, ...] FROM <stable_name> WHERE <tag_name> <[=|=<|>=|<>] values..> ([AND|OR] ...)
    
 
    It will list all the tables which satisfy the tag filter conditions. The tables are all created from this specific STable. TBNAME is a new keyword introduced, it is the table name associated with the STable. 
    
-
    SELECT COUNT(TBNAME) FROM <stable_name> WHERE <tag_name> <[=|=<|>=|<>] values..> ([AND|OR] …)
    
+
    SELECT COUNT(TBNAME) FROM <stable_name> WHERE <tag_name> <[=|=<|>=|<>] values..> ([AND|OR] ...)
    
 
    The above SQL statement will list the number of tables in a STable, which satisfy the filter condition.
    
 
    Management of Tags
    
 
    You can add, delete and change the tags for a STable, and you can change the tag value of a table. The SQL commands are listed below.  
    
-- 
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