SQL is a language for performing set operations and recursion is not one of them. Further, many database systems have limitations on recursion using stored procedures as a safety measure to prevent rogue code from running away with precious server resources. So, when working with SQL always think 'flat', not 'hierarchical'.

2009年8月3日 · pg_dump dbname -s -t table_to_clone > /tmp/temp.sql Than sed or vim of the file to change the table name and related stuff. Often is enough to replace table_to_clone with table_new_name. At creation, I usually prefix with table name indexes and triggers, so at this point I have nothing more to do. Now, from psql: begin work; \i /tmp/temp.sql

2014年9月27日 · I have the following 2 tables: CREATE TABLE [Names] ( [Id] INT PRIMARY KEY, [Name] VARCHAR(100) ) CREATE TABLE [Relationships] ( [Parent] [int] REFERENCES [Names]([Id

2012年12月14日 · This can be done with a recursive query. Here is something to get you started: with all_item_counts as ( select item, subitem, quantity as q, 0 as level from bom union all select all_item_counts.item, bom.subitem, quantity * q, level + 1 from all_item_counts join bom on bom.item = all_item_counts.subitem ) select item,subitem,sum(q) from all_item_counts group …

# At first you have to create Database CREATE DATABASE student_sql; # Next, specify the database to use USE student_sql; # Demo: create a table CREATE TABLE student_table( student_id INT PRIMARY KEY, name VARCHAR(20), major VARCHAR(20) ); # Describe the table describe student_table;

2010年7月29日 · @schmijos: actually it's implied, at best. "sql" does NOT mean "MS Sql Server" and it's irritating that so many people seem to think it's acceptable to use the generic term to specify a specific vendor. "sql" means Structured Query …

2015年6月16日 · You can use a recursive CTE where you in the anchor part get all rows and in the recursive part join to get the child rows. Remember the original Id aliased RootID from the anchor part and do sum aggregate in the main query grouped by RootID. SQL Fiddle. MS SQL Server 2012 Schema Setup:

2014年7月31日 · Hi i am new to oracle_sqldeveloper can you please give me the answer how to know the table structure and relationships of a database.

2010年3月24日 · If you want to copy the entire structure, you need to generate a Create Script of the table. You can use that script to create a new table with the same structure. You can then also dump the data into the new table if you need to. If you are using Enterprise Manager, just right-click the table and select copy to generate a Create Script.

2016年4月13日 · Tree structure data query in SQL Server. 2. SQL SERVER 2008 tree query. 1. Return Query Based on Tree ...