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docs:cdiwadkar16-patch-4-29 - minor 

grammatical, stylistic and one spelling change.
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Chait Diwadkar 2022-05-28 18:16:46 -07:00 committed by gccgdb1234
parent 7d479338b9
commit bfbf2b97c4
1 changed files with 13 additions and 13 deletions
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docs-en/12-taos-sql/10-json.md
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@ -4,7 +4,7 @@ title: JSON Type
## Syntax ## Syntax
1. Tag of JSON type 1. Tag of type JSON
```sql ```sql
create STable s1 (ts timestamp, v1 int) tags (info json); create STable s1 (ts timestamp, v1 int) tags (info json);
@ -12,7 +12,7 @@ title: JSON Type
create table s1_1 using s1 tags ('{"k1": "v1"}'); create table s1_1 using s1 tags ('{"k1": "v1"}');
``` ```
2. -> Operator of JSON 2. "->" Operator of JSON
```sql ```sql
select * from s1 where info->'k1' = 'v1'; select * from s1 where info->'k1' = 'v1';
@ -20,7 +20,7 @@ title: JSON Type
select info->'k1' from s1; select info->'k1' from s1;
``` ```
3. contains Operator of JSON 3. "contains" Operator of JSON
```sql ```sql
select * from s1 where info contains 'k2'; select * from s1 where info contains 'k2';
@ -30,7 +30,7 @@ title: JSON Type
## Applicable Operations ## Applicable Operations
1. When JSON data type is used in `where`, `match/nmatch/between and/like/and/or/is null/is no null` can be used but `in` can't be used. 1. When a JSON data type is used in `where`, `match/nmatch/between and/like/and/or/is null/is no null` can be used but `in` can't be used.
```sql ```sql
select * from s1 where info->'k1' match 'v*'; select * from s1 where info->'k1' match 'v*';
@ -42,9 +42,9 @@ title: JSON Type
select * from s1 where info->'k1' is not null; select * from s1 where info->'k1' is not null;
``` ```
2. Tag of JSON type can be used in `group by`, `order by`, `join`, `union all` and sub query, for example `group by json->'key'` 2. A tag of JSON type can be used in `group by`, `order by`, `join`, `union all` and sub query; for example `group by json->'key'`
3. `Distinct` can be used with tag of JSON type 3. `Distinct` can be used with a tag of type JSON
```sql ```sql
select distinct info->'k1' from s1; select distinct info->'k1' from s1;
@ -52,9 +52,9 @@ title: JSON Type
4. Tag Operations 4. Tag Operations
The value of JSON tag can be altered. Please note that the full JSON will be overriden when doing this. The value of a JSON tag can be altered. Please note that the full JSON will be overriden when doing this.
The name of JSON tag can be altered. A tag of JSON type can't be added or removed. The column length of a JSON tag can't be changed. The name of a JSON tag can be altered. A tag of JSON type can't be added or removed. The column length of a JSON tag can't be changed.
## Other Restrictions ## Other Restrictions
@ -64,17 +64,17 @@ title: JSON Type
- JSON format： - JSON format：
- The input string for JSON can be empty, i.e. "", "\t", or NULL, but can't be non-NULL string, bool or array. - The input string for JSON can be empty, i.e. "", "\t", or NULL, but it can't be non-NULL string, bool or array.
- object can be {}, and the whole JSON is empty if so. Key can be "", and it's ignored if so. - object can be {}, and the entire JSON is empty if so. Key can be "", and it's ignored if so.
- value can be int, double, string, boll or NULL, can't be array. Nesting is not allowed, that means value can't be another JSON. - value can be int, double, string, bool or NULL, and it can't be an array. Nesting is not allowed which means that the value of a key can't be JSON.
- If one key occurs twice in JSON, only the first one is valid. - If one key occurs twice in JSON, only the first one is valid.
- Escape characters are not allowed in JSON. - Escape characters are not allowed in JSON.
- NULL is returned if querying a key that doesn't exist in JSON. - NULL is returned when querying a key that doesn't exist in JSON.
- If a tag of JSON is the result of inner query, it can't be parsed and queried in the outer query. - If a tag of JSON is the result of inner query, it can't be parsed and queried in the outer query.
For example, the below SQL statements are not supported. For example, the SQL statements below are not supported.
```sql; ```sql;
select jtag->'key' from (select jtag from STable); select jtag->'key' from (select jtag from STable);