postgresql用身份证前6位建立分区
时间: 2024-01-04 10:03:56 浏览: 31
在 PostgreSQL 中,可以使用表分区技术实现数据分区。要使用身份证前6位来建立分区,可以按照以下步骤进行操作:
1. 创建一个父表,用于存储所有分区的元数据信息:
```sql
CREATE TABLE partition_parent (
id SERIAL PRIMARY KEY,
partition_name TEXT NOT NULL,
partition_start TEXT NOT NULL,
partition_end TEXT NOT NULL
);
```
2. 创建一个函数,用于根据身份证前6位来计算分区名称:
```sql
CREATE OR REPLACE FUNCTION partition_name_fn(id_num TEXT)
RETURNS TEXT AS $$
DECLARE
prefix TEXT;
BEGIN
prefix := SUBSTRING(id_num from 1 for 6);
RETURN 'partition_' || prefix;
END;
$$ LANGUAGE plpgsql;
```
3. 创建一个触发器,用于在插入数据时根据身份证前6位来将数据插入到对应的分区中:
```sql
CREATE OR REPLACE FUNCTION partition_insert_fn()
RETURNS TRIGGER AS $$
DECLARE
partition_name TEXT;
BEGIN
partition_name := partition_name_fn(NEW.id_num);
IF NOT EXISTS(SELECT relname FROM pg_class WHERE relname = partition_name) THEN
EXECUTE 'CREATE TABLE ' || partition_name || ' (LIKE ' || TG_TABLE_NAME || ' INCLUDING ALL)';
EXECUTE 'ALTER TABLE ' || partition_name || ' ADD CONSTRAINT ' || partition_name || '_pk PRIMARY KEY (id)';
EXECUTE 'ALTER TABLE ' || partition_name || ' ADD CONSTRAINT ' || partition_name || '_check CHECK (id_num >= ''' || partition_start || ''' AND id_num < ''' || partition_end || ''')';
EXECUTE 'ALTER TABLE ' || partition_name || ' INHERIT ' || TG_TABLE_NAME;
INSERT INTO partition_parent (partition_name, partition_start, partition_end) VALUES (partition_name, partition_start, partition_end);
END IF;
EXECUTE 'INSERT INTO ' || partition_name || ' SELECT ($1).*' USING NEW;
RETURN NULL;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER partition_insert_trg
BEFORE INSERT ON my_table
FOR EACH ROW EXECUTE FUNCTION partition_insert_fn();
```
在上面的代码中,我们假设要对名为 my_table 的表进行分区,其中包含一个名为 id_num 的列,用于存储身份证号码。触发器会在插入数据时根据身份证前6位来计算分区名称,并将数据插入到对应的分区中。同时,如果该分区还不存在,则会动态创建该分区,并将元数据信息插入到 partition_parent 表中。