问题描述
我有一个具有两个模式的 Oracle 数据库.一个是旧的，另一个是新的.我想用新模式的新列更新旧模式.
I've an Oracle database with two schemas. One is old and another is new. I would like to update the old schema with the new columns of the new schema.
我通过以下查询获得了更改的表.
I get the tables which have changes with the following query.
select distinct table_name
from
(
select table_name,column_name
from all_tab_cols
where owner = 'SCHEMA_1'
minus
select table_name,column_name
from all_tab_cols
where owner = 'SCHEMA_2'
)
通过这个查询，我得到了表格.如何使用新列更新旧模式表?我不需要数据，只需要列.
With this query I get the tables. How can I update the old schema tables with the new columns? I don't need the data, just the columns.
推荐答案
架构比较工具是个好主意.数据库架构比大多数人认为的要复杂得多，两个数据库架构之间的每一个差异都有可能导致错误.
A schema comparison tool is a good idea. The database schema is far more complicated than most people give credit, and every difference between two database schemas has the potential to cause bugs.
如果您仍然热衷于自己做，我发现的最佳方法是将架构定义提取到文本中，然后运行文本比较.只要所有内容都按字母顺序排序，您就可以使用 Microsoft Word(或 FC.EXE、DIFF 或同等文件)中的比较文档功能来突出显示差异.
If you're still keen to do it yourself, the best approach I've found is to extract the schema definitions to text, then run a text compare. As long as everything is sorted alphabetically, you can then use Compare Documents feature in Microsoft Word (or FC.EXE, DIFF or equivalent), to highlight the differences.
以下 SQLPlus 脚本按字母顺序输出架构定义，以便进行比较.有两个部分.第一部分列出了每一列，格式为:
The following SQLPlus script outputs the schema definition alphabetically, to allow comparison. There are two sections. The first section lists each column, in the format:
table_name.column_name: data_type = data_default <nullable>
第二部分列出了索引和约束，如下:
The second section lists indexes and constraints, as follows:
PK constraint_name on table_name (pk_column_list)
FK constraint_name on table_name (fk_column_list)
CHECK constraint_name on table_name (constraint_definition)
该脚本可作为提取某些 Oracle 架构详细信息的有用参考.当您在客户站点并且没有可用的常用工具时，或者当安全策略阻止您直接从您自己的 PC 访问客户站点数据库时，这可能是一个很好的知识.
The script serves as a useful references for extracting some of the Oracle schema details. This can be good knowledge to have when you're out at client sites and you don't have your usual tools available, or when security policies prevent you from accessing a client site database directly from your own PC.
set serveroutput on;
set serveroutput on size 1000000;
declare
rowcnt pls_integer := 0;
cursor c_column is
select table_name, column_name, data_type,
data_precision, data_length, data_scale,
data_default, nullable,
decode(data_scale, null, null, ',') scale_comma,
decode(default_length, null, null, '= ') default_equals
from all_tab_columns where owner = 'BCC'
order by table_name, column_name;
cursor c_constraint is
select c.table_name, c.constraint_name,
decode(c.constraint_type,
'P','PK',
'R','FK',
'C','CHECK',
c.constraint_type) constraint_type,
c.search_condition,
cc.column_1||cc.comma_2||cc.column_2||cc.comma_3||cc.column_3||cc.comma_4||cc.column_4||
cc.comma_5||cc.column_5||cc.comma_6||cc.column_6||cc.comma_7||cc.column_7 r_columns
from all_constraints c,
( select owner, table_name, constraint_name, nvl(max(position),0) max_position,
max( decode( position, 1, column_name, null ) ) column_1,
max( decode( position, 2, decode(column_name, null, null, ',' ), null ) ) comma_2,
max( decode( position, 2, column_name, null ) ) column_2,
max( decode( position, 3, decode(column_name, null, null, ',' ), null ) ) comma_3,
max( decode( position, 3, column_name, null ) ) column_3,
max( decode( position, 4, decode(column_name, null, null, ',' ), null ) ) comma_4,
max( decode( position, 4, column_name, null ) ) column_4,
max( decode( position, 5, decode(column_name, null, null, ',' ), null ) ) comma_5,
max( decode( position, 5, column_name, null ) ) column_5,
max( decode( position, 6, decode(column_name, null, null, ',' ), null ) ) comma_6,
max( decode( position, 6, column_name, null ) ) column_6,
max( decode( position, 7, decode(column_name, null, null, ',' ), null ) ) comma_7,
max( decode( position, 7, column_name, null ) ) column_7
from all_cons_columns
group by owner, table_name, constraint_name ) cc
where c.owner = 'BCC'
and c.generated != 'GENERATED NAME'
and cc.owner = c.owner
and cc.table_name = c.table_name
and cc.constraint_name = c.constraint_name
order by c.table_name,
decode(c.constraint_type,
'P','PK',
'R','FK',
'C','CHECK',
c.constraint_type) desc,
c.constraint_name;
begin
for c_columnRow in c_column loop
dbms_output.put_line(substr(c_columnRow.table_name||'.'||c_columnRow.column_name||': '||
c_columnRow.data_type||'('||
nvl(c_columnRow.data_precision, c_columnRow.data_length)||
c_columnRow.scale_comma||c_columnRow.data_scale||') '||
c_columnRow.default_equals||c_columnRow.data_default||
' <'||c_columnRow.nullable||'>',1,255));
rowcnt := rowcnt + 1;
end loop;
for c_constraintRow in c_constraint loop
dbms_output.put_line(substr(c_constraintRow.constraint_type||' '||c_constraintRow.constraint_name||' on '||
c_constraintRow.table_name||' ('||
c_constraintRow.search_condition||
c_constraintRow.r_columns||') ',1,255));
if length(c_constraintRow.constraint_type||' '||c_constraintRow.constraint_name||' on '||
c_constraintRow.table_name||' ('||
c_constraintRow.search_condition||
c_constraintRow.r_columns||') ') > 255 then
dbms_output.put_line('... '||substr(c_constraintRow.constraint_type||' '||c_constraintRow.constraint_name||' on '||
c_constraintRow.table_name||' ('||
c_constraintRow.search_condition||
c_constraintRow.r_columns||') ',256,251));
end if;
rowcnt := rowcnt + 1;
end loop;
end;
/
很遗憾，有一些限制:
- data_defaults 中嵌入的回车符和空格以及检查约束定义可能会突出显示为差异，即使它们对架构的影响为零.
- 不包括备用键、唯一索引或性能索引.这将需要脚本中的第三个 SELECT 语句，引用 all_ind_columns 和 all_indexes 目录视图.
- 不包括安全详细信息、同义词、包、触发器等.最好使用类似于您最初建议的方法来比较包和触发器.架构定义的其他方面可以添加到上述脚本中.
- 上面的 FK 定义标识了引用的外键列，而不是 PK 或被引用的表.还有一个我一直没时间做的细节.
即使您不使用脚本.玩这些东西会给技术人员带来一定的乐趣.;-)
Even if you don't use the script. There's a certain techie pleasure in playing with this stuff. ;-)
马修
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