,我们可以看到,JSON Path一般结合匹配的函数或者操作符使用,这时可以将其看成简单的字符串参数。...作为操作符PG中关于JSON PATH有那些相关的功能和函数在JSON章节中,我们已经提到,下面由两个操作符,需要配合JSON Path进行使用:jsonb @?...在路径字符串中,还可以...
$obj->body = 'another post'; $obj->id = 21; $obj->approved = true; $obj->favorite_count = 1; $obj->status = NULL; echo json_encode($obj); 1. 2. 3. 4. 5. 6.输出 { "body":"another post", "id":21, "approved":true, "favorite_count":1, "status":null } 1. 2. 3...
然后就可以自动转换了 例如List<XXX>的Json可以如下使用： @TableField(typeHandler = JsonListHandler.cl...
ROUND(COUNT(view_50.amount_in)::NUMERIC / NULLIF(COUNT(view_50.amount_out)::NUMERIC, 0),2) AS out_divide_in, 1. 使用COLA / NULLIF(COLB,0)后, 如果 COLB 为0, 产生的输出就是NULL 空数组解析为默认值 使用*jsonb_array_elements_text()*可以将一个 JSONB 类型的列解析为多行 – 这是一...
-+--- (0 rows) --插入超长数据 postgres=# insert into toast values('plain00000', 'main11111', repeat('external22222', 1000), 'extended33333'); INSERT 0 1 ---toast中已经有数据了 postgres=# select count(*) from pg_toast.pg_toast_821650; count --- 7 (1 row) 通过以下sql查看各种数...
This one includes regexp_split_to_table, strpos, lag() functions and COUNT(DISTINCT). Also, a great example of using a DO function with RAISE NOTICE. Advent of Code - Day 7 SQL Solutions for Day 7 of Advent of Code. This one includes recursive queries, text arrays, and tons of ...
query "mentions" { sql = <<EOQ with names as ( select unnest( $1::text[] ) as name ), counts as ( select name, ( select count(*) from hn where title ~* name and (extract(epoch from now() - time::timestamptz) / 60)::int betw...
selectindrelid::regclassastablename,array_agg(indexrelid::regclass)asindexesfrompg_indexgroupbyindrelid,indkeyhavingcount(*)>1; 检查长期未使用的索引。 mydb=# select relname,indexrelname,idx_scan from pg_catalog.pg_stat_user_indexes; 检查无效的索引。
joinjson_to_recordset(('{"data":[{"name": "male","code": "1"},{"name": "blonde","code": "2"}]}')::json->'data')asj(codeint) 13 ONu.group_id= j.code 14 ) Q 15 GROUPBYuser_id 16 HavingCount(1) = json_array_length(('{"data":[{"name": "male","code": "1"},...
(queryDesc=0x1a64a68, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:579 #9 0x00000000007fec25 in ExecutorRun (queryDesc=queryDesc@entry=0x1a64a68, direction=direction@entry=ForwardScanDirection, count=count@entry=0, execute_once=<optimized out>) at exec...