Associative array 关联数组有点类似于java中的Map,只是在PL/SQL中,关联数组索引的数据类型只能是string类型(VARCHAR2,VARCHAR,STRING,LONG)和PLS_INTEGER。关联数组不存在为NULL的情况,所以你不能使用IS NULL和IS NOT NULL去测试它,否则无法通过编译。 定义关联数组的方式如下: TYPE 关联数组类型名称 IS TABLE OF ...
PL/pgSQL支持的控制结构与其他语言几乎差不多,比如:条件、循环、异常等,下面就分别介绍控制结构的使用。1、条件对于条件控制结构,支持IF与CASE两种,IF语句有如下三种写法:if ... then ... end if if ... then ... e postgresql if判空 控制结构
CopyMultiInsertInfoIsEmpty(&multiInsertInfo)) { /* * Flush pending inserts if this partition can't use * batching, so rows are visible to triggers etc. */ CopyMultiInsertInfoFlush(&multiInsertInfo, resultRelInfo, &processed); } if (bistate != NULL) ReleaseBulkInsertStatePin(bistate);...
At the moment, our scripts output all the double quotes manually, so we could edit the scripts to instead output no quotes, then consider a lack of double quotes as evidence that the field should be null, but as of right now I haven't tested if postgres would easily understand that. Pr...
| 2 | (null) | 1 | 0 | 0 | | 3 | | 0 | 0 | 1 | | 4 | x | 0 | 0 | 0 | This tells us that the empty string was treated as a NULL when inserted into the table, and that it can't be compared to regular values as if it were an empty string because it's a ...
fc->is_not_null = false; fc->colexpr = NULL; fc->coldefexpr = NULL; fc->location = @1; foreach(option, $3) { DefElem *defel = (DefElem *) lfirst(option); if (strcmp(defel->defname, "default") == 0) { if (fc->coldefexpr != NULL) ereport(ERROR, (errcode(ERRCODE...
* If he writes ON() then only "quals" is set. Note that NATURAL/USING * are not equivalent to ON() since they also affect the output column list. * * alias is an Alias node representing the AS alias-clause attached to the * join expression, or NULL if no clause. NB: presence ...
A null value is treated as an empty string. I treats the argument value as an SQL identifier, double-quoting it if necessary. It is an error for the value to be null (equivalent to quote_ident). L quotes the argument value as an SQL literal. A null value is displayed as the string...
The field that is used for data sharding when PostgreSQL Reader reads data. If you configure this parameter, the source table is sharded based on the value of this parameter. Data Integration then runs parallel threads to read data. This way, data can be synchronized more efficiently. ...
Then, from the top menu, choose Tools→Backup Globals. pgAdmin doesn’t give you control over which global objects to back up, as the command-line interface does. pgAdmin backs up all tablespaces and roles. If you ever want to back up the entire server, perform a pg_dumpall by going ...