@@ -1335,3 +1335,24 @@ Is not null supports all types of columns. Non-null expression is < > "" and onl
...
@@ -1335,3 +1335,24 @@ Is not null supports all types of columns. Non-null expression is < > "" and onl
select jtag->'key' from (select jtag from stable) where jtag->'key'>0
select jtag->'key' from (select jtag from stable) where jtag->'key'>0
```
```
## Escape character description
- Special Character Escape Sequences
| Escape Sequence | **Character Represented by Sequence** |
| :--------: | ------------------- |
| `\'` | A single quote (') character |
| `\"` | A double quote (") character |
| \n | A newline (linefeed) character |
| \r | A carriage return character |
| \t | A tab character |
| `\\` | A backslash (\) character |
| `\%` | A % character; see note following the table |
| `\_` | A _ character; see note following the table |
- Escape character usage rules
- The escape characters that in a identifier (database name, table name, column name)
1. Normal identifier： The wrong identifier is prompted directly, because the identifier must be numbers, letters and underscores, and cannot start with a number.
2. Backquote`` identifier： Keep it as it is.
- The escape characters that in a data
3. The escape character defined above will be escaped (% and _ see the description below). If there is no matching escape character, the escape character will be ignored.
4. The `\%` and `\_` sequences are used to search for literal instances of % and _ in pattern-matching contexts where they would otherwise be interpreted as wildcard characters.If you use `\%` or `\_` outside of pattern-matching contexts, they evaluate to the strings `\%` and `\_`, not to % and _.
sql="select last(*) from ( select sum(i1) from st where ts>='2017-07-14 11:40:00' and ts<'2017-07-14 12:40:00' interval(10m) order by ts desc );"# desc
sql="select last(*) from ( select sum(i1) from st where ts>='2017-07-14 11:40:00' and ts<'2017-07-14 12:40:00' interval(10m) order by ts desc );"# desc
tdSql.waitedQuery(sql,1,WAITS)
tdSql.waitedQuery(sql,1,WAITS)
tdSql.checkData(0,1,192419100)
tdSql.checkData(0,1,192419100)
# add parent query order by
# first
sql="select first(*) from (select first(i1) from st interval(10m) order by ts asc) order by ts desc;"
tdSql.waitedQuery(sql,1,WAITS)
tdSql.checkData(0,1,0)
sql="select first(*) from (select first(i1) from st interval(10m) order by ts desc) order by ts asc;"
tdSql.waitedQuery(sql,1,WAITS)
tdSql.checkData(0,1,0)
# last
sql="select last(*) from (select first(i1) from st interval(10m) order by ts asc) order by ts desc;"
tdSql.waitedQuery(sql,1,WAITS)
tdSql.checkData(0,1,229400)
sql="select last(*) from (select first(i1) from st interval(10m) order by ts desc) order by ts asc;"
tdSql.query(f'select {table_name_sub1},{table_name_sub2},{table_name_sub3},{table_name_sub4},{table_name_sub5},{table_name_sub6},{table_name_sub7},{table_name_sub8},{table_name_sub9} from {table_name} where tbname in ("{table_name_sub1}","{table_name_sub2}","{table_name_sub3}","{table_name_sub4}","{table_name_sub5}","{table_name_sub6}","{table_name_sub7}","{table_name_sub8}","{table_name_sub9}") and ts >= "1980-01-01 00:00:00.000"')
tdSql.query(f'select {table_name_sub1},{table_name_sub2},{table_name_sub3},{table_name_sub4},{table_name_sub5},{table_name_sub6},{table_name_sub7},{table_name_sub8},{table_name_sub9} from {table_name} where tbname in ("{table_name_sub1}","{table_name_sub2}","{table_name_sub3}","{table_name_sub4}","{table_name_sub5}","{table_name_sub6}","{table_name_sub7}","{table_name_sub8}","{table_name_sub9}") and ts >= "1980-01-01 00:00:00.000"')
