我已经在postgreSQL中创建了一个表。我想查看用于创建表的SQL语句,但无法找出它。
如何通过命令行或SQL语句获得Postgres中现有表的创建表SQL语句?
我已经在postgreSQL中创建了一个表。我想查看用于创建表的SQL语句,但无法找出它。
如何通过命令行或SQL语句获得Postgres中现有表的创建表SQL语句?
当前回答
另一个简单的选择是使用[HeidiSQL client][1]作为PostgreSQL数据库。
如何进入列出所有数据库和表的数据库选项卡。
单击想要查看DDL/创建特定表的语句的任何表/视图。
现在这个客户端为你在右边窗口的桌子上做以下工作:
第一个窗口将用于表中的数据
第二个是SQL主机信息
第三是数据库级别的信息,比如哪些表,大小是多少
第四,我们更关心的表/视图信息选项卡将有create table语句随时为您提供。
我不能在快照中显示你在处理机密数据,自己试试,让我知道如果你们发现了任何问题。
其他回答
pg_dump -t 'schema-name.table-name' --schema-only database-name
更多信息-在手册。
如果您不想创建函数,而只想让查询创建一个基本的表结构,这里有一个解决方案。
select 'CREATE TABLE ' || table_name ||'(' ||STRING_AGG (
column_name || ' ' || data_type ,
','
ORDER BY
table_name,
ordinal_position
) ||');'
from
information_schema.columns
where table_schema = 'public'
group by
table_name
甚至根据@vkkeeper的响应进行了更多的修改。增加了从特定模式查询表的可能性。
CREATE OR REPLACE FUNCTION public.describe_table(p_schema_name character varying, p_table_name character varying)
RETURNS SETOF text AS
$BODY$
DECLARE
v_table_ddl text;
column_record record;
table_rec record;
constraint_rec record;
firstrec boolean;
BEGIN
FOR table_rec IN
SELECT c.relname, c.oid FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE relkind = 'r'
AND n.nspname = p_schema_name
AND relname~ ('^('||p_table_name||')$')
ORDER BY c.relname
LOOP
FOR column_record IN
SELECT
b.nspname as schema_name,
b.relname as table_name,
a.attname as column_name,
pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
CASE WHEN
(SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
ELSE
''
END as column_default_value,
CASE WHEN a.attnotnull = true THEN
'NOT NULL'
ELSE
'NULL'
END as column_not_null,
a.attnum as attnum,
e.max_attnum as max_attnum
FROM
pg_catalog.pg_attribute a
INNER JOIN
(SELECT c.oid,
n.nspname,
c.relname
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.oid = table_rec.oid
ORDER BY 2, 3) b
ON a.attrelid = b.oid
INNER JOIN
(SELECT
a.attrelid,
max(a.attnum) as max_attnum
FROM pg_catalog.pg_attribute a
WHERE a.attnum > 0
AND NOT a.attisdropped
GROUP BY a.attrelid) e
ON a.attrelid=e.attrelid
WHERE a.attnum > 0
AND NOT a.attisdropped
ORDER BY a.attnum
LOOP
IF column_record.attnum = 1 THEN
v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
ELSE
v_table_ddl:=v_table_ddl||',';
END IF;
IF column_record.attnum <= column_record.max_attnum THEN
v_table_ddl:=v_table_ddl||chr(10)||
' '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
END IF;
END LOOP;
firstrec := TRUE;
FOR constraint_rec IN
SELECT conname, pg_get_constraintdef(c.oid) as constrainddef
FROM pg_constraint c
WHERE conrelid=(
SELECT attrelid FROM pg_attribute
WHERE attrelid = (
SELECT oid FROM pg_class WHERE relname = table_rec.relname
AND relnamespace = (SELECT ns.oid FROM pg_namespace ns WHERE ns.nspname = p_schema_name)
) AND attname='tableoid'
)
LOOP
v_table_ddl:=v_table_ddl||','||chr(10);
v_table_ddl:=v_table_ddl||'CONSTRAINT '||constraint_rec.conname;
v_table_ddl:=v_table_ddl||chr(10)||' '||constraint_rec.constrainddef;
firstrec := FALSE;
END LOOP;
v_table_ddl:=v_table_ddl||');';
RETURN NEXT v_table_ddl;
END LOOP;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
生成创建特定表背后的SQL (DDL)。 我们可以简单地使用这个SQL查询-
SHOW TABLE your_schema_name.your_table_name
这是这个老问题的另一个解决方案。多年来,关于这个问题有许多优秀的答案,我的尝试在很大程度上借鉴了它们。
我使用安德烈·列别登科的解决方案作为起点,因为它的输出已经非常接近我的要求。
特点:
following common practice I have moved the foreign key constraints outside the table definition. They are now included as ALTER TABLE statements at the bottom. The reason is that a foreign key can also link to a column of the same table. In that fringe case the constraint can only be created after the table creation is completed. The create table statement would throw an error otherwise. The layout and indenting looks nicer now (at least to my eye) Drop command (commented out) in the header of the definition The solution is offered here as a plpgsql function. The algorithm does however not use any procedural language. The function just wraps one single query that can be used in a pure sql context as well. removed redundant subqueries Identifiers are now quoted if they are identical to reserved postgresql language elements replaced the string concatenation operator || with the appropriate string functions to improve performance, security and readability of the code. Note: the || operator produces NULL if one of the combined strings is NULL. It should only be used when that is the desired behaviour. (check out the usage in the code below for an example)
CREATE OR REPLACE FUNCTION public.wmv_get_table_definition (
p_schema_name character varying,
p_table_name character varying
)
RETURNS SETOF TEXT
AS $BODY$
BEGIN
RETURN query
WITH table_rec AS (
SELECT
c.relname, n.nspname, c.oid
FROM
pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE
relkind = 'r'
AND n.nspname = p_schema_name
AND c.relname LIKE p_table_name
ORDER BY
c.relname
),
col_rec AS (
SELECT
a.attname AS colname,
pg_catalog.format_type(a.atttypid, a.atttypmod) AS coltype,
a.attrelid AS oid,
' DEFAULT ' || (
SELECT
pg_catalog.pg_get_expr(d.adbin, d.adrelid)
FROM
pg_catalog.pg_attrdef d
WHERE
d.adrelid = a.attrelid
AND d.adnum = a.attnum
AND a.atthasdef) AS column_default_value,
CASE WHEN a.attnotnull = TRUE THEN
'NOT NULL'
ELSE
'NULL'
END AS column_not_null,
a.attnum AS attnum
FROM
pg_catalog.pg_attribute a
WHERE
a.attnum > 0
AND NOT a.attisdropped
ORDER BY
a.attnum
),
con_rec AS (
SELECT
conrelid::regclass::text AS relname,
n.nspname,
conname,
pg_get_constraintdef(c.oid) AS condef,
contype,
conrelid AS oid
FROM
pg_constraint c
JOIN pg_namespace n ON n.oid = c.connamespace
),
glue AS (
SELECT
format( E'-- %1$I.%2$I definition\n\n-- Drop table\n\n-- DROP TABLE IF EXISTS %1$I.%2$I\n\nCREATE TABLE %1$I.%2$I (\n', table_rec.nspname, table_rec.relname) AS top,
format( E'\n);\n\n\n-- adempiere.wmv_ghgaudit foreign keys\n\n', table_rec.nspname, table_rec.relname) AS bottom,
oid
FROM
table_rec
),
cols AS (
SELECT
string_agg(format(' %I %s%s %s', colname, coltype, column_default_value, column_not_null), E',\n') AS lines,
oid
FROM
col_rec
GROUP BY
oid
),
constrnt AS (
SELECT
string_agg(format(' CONSTRAINT %s %s', con_rec.conname, con_rec.condef), E',\n') AS lines,
oid
FROM
con_rec
WHERE
contype <> 'f'
GROUP BY
oid
),
frnkey AS (
SELECT
string_agg(format('ALTER TABLE %I.%I ADD CONSTRAINT %s %s', nspname, relname, conname, condef), E';\n') AS lines,
oid
FROM
con_rec
WHERE
contype = 'f'
GROUP BY
oid
)
SELECT
concat(glue.top, cols.lines, E',\n', constrnt.lines, glue.bottom, frnkey.lines, ';')
FROM
glue
JOIN cols ON cols.oid = glue.oid
LEFT JOIN constrnt ON constrnt.oid = glue.oid
LEFT JOIN frnkey ON frnkey.oid = glue.oid;
END;
$BODY$
LANGUAGE plpgsql;