如何编写从CSV文件导入数据并填充表的存储过程?


当前回答

如何将CSV文件数据导入PostgreSQL表

步骤:

Need to connect a PostgreSQL database in the terminal psql -U postgres -h localhost Need to create a database create database mydb; Need to create a user create user siva with password 'mypass'; Connect with the database \c mydb; Need to create a schema create schema trip; Need to create a table create table trip.test(VendorID int,passenger_count int,trip_distance decimal,RatecodeID int,store_and_fwd_flag varchar,PULocationID int,DOLocationID int,payment_type decimal,fare_amount decimal,extra decimal,mta_tax decimal,tip_amount decimal,tolls_amount int,improvement_surcharge decimal,total_amount ); Import csv file data to postgresql COPY trip.test(VendorID int,passenger_count int,trip_distance decimal,RatecodeID int,store_and_fwd_flag varchar,PULocationID int,DOLocationID int,payment_type decimal,fare_amount decimal,extra decimal,mta_tax decimal,tip_amount decimal,tolls_amount int,improvement_surcharge decimal,total_amount) FROM '/home/Documents/trip.csv' DELIMITER ',' CSV HEADER; Find the given table data select * from trip.test;

其他回答

看看这篇短文吧。


解决方案如下:

创建你的表:

CREATE TABLE zip_codes
(ZIP char(5), LATITUDE double precision, LONGITUDE double precision,
CITY varchar, STATE char(2), COUNTY varchar, ZIP_CLASS varchar);

将数据从CSV文件复制到表中:

COPY zip_codes FROM '/path/to/csv/ZIP_CODES.txt' WITH (FORMAT csv);

您还可以使用pgAdmin,它提供了一个GUI来执行导入。这在这个SO线程中显示。使用pgAdmin的优点是它也适用于远程数据库。

不过,与前面的解决方案非常相似,您需要在数据库中已经有表。每个人都有自己的解决方案,但我通常在Excel中打开CSV文件,复制标题,在不同的工作表上粘贴特殊的换位,在下一列上放置相应的数据类型,然后将其复制并粘贴到文本编辑器中,并使用适当的SQL表创建查询,如下所示:

CREATE TABLE my_table (
    /* Paste data from Excel here for example ... */
    col_1 bigint,
    col_2 bigint,
    /* ... */
    col_n bigint
)

在Python中,你可以使用这段代码自动创建带有列名的PostgreSQL表:

import pandas, csv

from io import StringIO
from sqlalchemy import create_engine

def psql_insert_copy(table, conn, keys, data_iter):
    dbapi_conn = conn.connection
    with dbapi_conn.cursor() as cur:
        s_buf = StringIO()
        writer = csv.writer(s_buf)
        writer.writerows(data_iter)
        s_buf.seek(0)
        columns = ', '.join('"{}"'.format(k) for k in keys)
        if table.schema:
            table_name = '{}.{}'.format(table.schema, table.name)
        else:
            table_name = table.name
        sql = 'COPY {} ({}) FROM STDIN WITH CSV'.format(table_name, columns)
        cur.copy_expert(sql=sql, file=s_buf)

engine = create_engine('postgresql://user:password@localhost:5432/my_db')

df = pandas.read_csv("my.csv")
df.to_sql('my_table', engine, schema='my_schema', method=psql_insert_copy)

它的速度也相对较快。我可以在大约4分钟内导入330多万行。

DBeaver社区版(DBeaver .io)使得连接到数据库,然后导入CSV文件上传到PostgreSQL数据库变得很简单。它还可以方便地发出查询、检索数据以及将结果集下载为CSV、JSON、SQL或其他常见数据格式。

它是一个面向SQL程序员、dba和分析师的自由/开源多平台数据库工具,支持所有流行的数据库:MySQL、PostgreSQL、SQLite、Oracle、DB2、SQL Server、Sybase、MS Access、Teradata、Firebird、Hive、Presto等。对于Postgres的TOAD, SQL Server的TOAD,或者Oracle的TOAD,它是一个可行的自由/开源软件竞争对手。

I have no affiliation with DBeaver. I love the price (FREE!) and full functionality, but I wish they would open up this DBeaver/Eclipse application more and make it easy to add analytics widgets to DBeaver / Eclipse, rather than requiring users to pay for the $199 annual subscription just to create graphs and charts directly within the application. My Java coding skills are rusty and I don't feel like taking weeks to relearn how to build Eclipse widgets, (only to find that DBeaver has probably disabled the ability to add third-party widgets to the DBeaver Community Edition.)

COPY table_name FROM 'path/to/data.csv' DELIMITER ',' CSV HEADER;