dynamic-sql

问题 I am writing a PL/SQL procedure that needs to to dynamically generate some queries, one of which involves creating a temporary table using results from a query taken as a parameter. CREATE OR REPLACE PROCEDURE sqlout(query IN VARCHAR2) IS BEGIN EXECUTE IMMEDIATE 'CREATE GLOBAL TEMPORARY TABLE tmp_tab AS (' || query || ');'; END; It compiles correctly, but even with very simple queries such as with: BEGIN sqlout('SELECT * FROM DUAL'); END; IT throws ORA-00911: invalid character . If I run the

问题 CREATE OR REPLACE FUNCTION getParentLtree(parent_id bigint, tbl_name varchar) RETURNS ltree AS $BODY$ DECLARE parent_ltree ltree; BEGIN -- This works fine: -- select into parent_ltree l_tree from tbl1 where id = parent_id; EXECUTE format('select into parent_ltree l_tree from %I where id = %I', tbl_name,parent_id); RETURN parent_ltree; END; $BODY$ LANGUAGE plpgsql; There are 2 issues in above function: parent_id is integer but it is replaced with quotes? What is the correct format specifier

问题 I am having difficulties writing a Postgres function, as I am not familiar with it. I have multiple tables to import into Postgres with this format: id | 1960 | 1961 | 1962 | 1963 | ... ____________________________________ 1 23 45 87 99 2 12 31 ... which I need to convert into this format: id | year | value _________________ 1 1960 23 1 1961 45 1 1962 87 ... 2 1960 12 2 1961 31 ... I would imagine the function too to read like this: SELECT all-years FROM imported_table; CREATE a new_table;

问题 I tried to use a function to set the n_distinct value for a table. The code is as follows: create temporary table _temp ( id integer ); create function pg_temp.setdistinct(_cnt real) returns void as $$ begin alter table _temp alter column id set (n_distinct=_cnt); end $$ language plpgsql; select pg_temp.setdistinct(1000); Yet receive the following errors: ERROR: invalid value for floating point option "n_distinct": _cnt CONTEXT: SQL statement "alter table _temp alter column id set (n_distinct

问题 Why do I get this error Procedure expects parameter '@statement' of type 'ntext/nchar/nvarchar'. when I try to use sp_executesql? 回答1: Sounds like you're calling sp_executesql with a VARCHAR statement, when it needs to be NVARCHAR. e.g. This will give the error because @SQL needs to be NVARCHAR DECLARE @SQL VARCHAR(100) SET @SQL = 'SELECT TOP 1 * FROM sys.tables' EXECUTE sp_executesql @SQL So: DECLARE @SQL NVARCHAR(100) SET @SQL = 'SELECT TOP 1 * FROM sys.tables' EXECUTE sp_executesql @SQL

问题 I want to select column names but I don't know the table structure ahead of time and it may change so I can't just hard code the select statement with column names. I also do NOT want to select every column. Is there and easy way to do this? My thoughts are it's some kind of combination of these two queries but my SQL is not that good. SHOW COLUMNS FROM table_name; SELECT * FROM table_name; I tried using a sub select but it didn't work. Nothing seems to happen, I don't get an error I just get

问题 I have the following dynamic query which is working fine without the WHERE clause, which is expecting UNIQUEIDENTIFIER . When I pass it in, I don't get a result. I tried CAST and CONVERT , but no result. I might be doing it wrong, can anybody help? CREATE PROCEDURE [dbo].[sp_Test1] /* 'b0da56dc-fc73-4c0e-85f7-541e3e8f249d' */ ( @p_CreatedBy UNIQUEIDENTIFIER ) AS DECLARE @sql NVARCHAR(4000) SET @sql =' DECLARE @p_CreatedBY UNIQUEIDENTIFIER SELECT DateTime, Subject, CreatedBy FROM ( SELECT

问题 I have the following dynamic query which is working fine without the WHERE clause, which is expecting UNIQUEIDENTIFIER . When I pass it in, I don't get a result. I tried CAST and CONVERT , but no result. I might be doing it wrong, can anybody help? CREATE PROCEDURE [dbo].[sp_Test1] /* 'b0da56dc-fc73-4c0e-85f7-541e3e8f249d' */ ( @p_CreatedBy UNIQUEIDENTIFIER ) AS DECLARE @sql NVARCHAR(4000) SET @sql =' DECLARE @p_CreatedBY UNIQUEIDENTIFIER SELECT DateTime, Subject, CreatedBy FROM ( SELECT

问题 I'm trying to switch the current database with a SQL statement. I have tried the following, but all attempts failed: USE @DatabaseName EXEC sp_sqlexec @Sql -- where @Sql = 'USE [' + @DatabaseName + ']' To add a little more detail. EDIT: I would like to perform several things on two separate database, where both are configured with a variable. Something like this: USE Database1 SELECT * FROM Table1 USE Database2 SELECT * FROM Table2 回答1: exec sp_execsql @Sql The DB change only lasts for the

问题 I'm trying to switch the current database with a SQL statement. I have tried the following, but all attempts failed: USE @DatabaseName EXEC sp_sqlexec @Sql -- where @Sql = 'USE [' + @DatabaseName + ']' To add a little more detail. EDIT: I would like to perform several things on two separate database, where both are configured with a variable. Something like this: USE Database1 SELECT * FROM Table1 USE Database2 SELECT * FROM Table2 回答1: exec sp_execsql @Sql The DB change only lasts for the