Any ideas about this problem's automization...

Question

Hi all
Please suggest any sql query for below problem:
I want to compare two schema tables(same in all schemas but altered late in either case) to display the differences in schemas. for this we can use TOAD SOFTWARE but it is very easy to compare the schema using this software but difficult to display the details (differences) according to my requirement. so can you anybody suggest any query to extract the following model:
for example:
Schema1 = emp table
schema2 = emp table
desc emp in schema1:
empno number(10) notnull
ename varchar2(20)
sal number(30)
desc emp in schema2:
empno number(10) notnull
empname varchar2(19) notnull
sal number(30)
out put requirement:
Schema |TableName| Fields | Datatype | Null/Notnull | Constraint Schema2|TableName| Fields | Datatype | Null/Notnull
EMP EMPNO NOTNULL EMP EMPNO NOT NULL
SAL SAL
ENAME VARCHAR2(20) EMPNAME VARCHAR2(19) "ADDITIONAL
                                                       (name change)      NOT NULL
                                                                 CONSTRAINT"
let me explain above example, in the given two same tables in different schema, in the output
those fields which are matched in terms of all i.e field name,datatype,constraint,null/notnull
should be displayed first.
Then those field which have differences should be displayed by giving appropriate comments
like "colmn name changed if there is difference between col names in both schemas"
In some cases, we cannot find the table in one schema, it should print "table not found on the schema2 side in the above output
Very important note is that Schema1 should reflect same as
schema2 tables.
One more thing is in the above output : for ename field only datatype displayed, this is because for those
fields which have change in schema2, for that colomns only we have to display the datatype.
Thanks in advance
prasanth

Answer 1

Some sample code to get you started ...
SQL> desc core.emp
Name                                      Null?    Type
EMPNO                                     NOT NULL NUMBER(10)
ENAME                                              VARCHAR2(20)
SAL                                                NUMBER(30)
DT                                        NOT NULL DATE
 
SQL> desc flip.emp
Name                                      Null?    Type
EMPNO                                     NOT NULL NUMBER(10)
EMPNAME                                   NOT NULL VARCHAR2(19)
SAL                                                NUMBER(30)
DT                                                 DATE
 
SQL> set lines 120
SQL> col owner format a10
SQL> col table_name format a10
SQL> col column_name format a10
SQL> col data_type format a10
SQL>
SQL> with t1 as
  2       ( SELECT 1               src1
  3               ,to_number(null) src2
  4               ,owner
  5               ,table_name
  6               ,column_name
  7               ,data_type
  8               ,data_length
  9               ,data_scale
10               ,nullable
11         FROM  dba_tab_columns
12         WHERE owner      = 'CORE'
13         AND   table_name = 'EMP'
14       )
15      ,t2 as
16       ( SELECT to_number(null) src1
17               ,1               src2
18               ,owner
19               ,table_name
20               ,column_name
21               ,data_type
22               ,data_length
23               ,data_scale
24               ,nullable
25         FROM  dba_tab_columns
26         WHERE owner      = 'FLIP'
27         AND   table_name = 'EMP'
28       )
29      ,src as
30       ( select table_name
31               ,column_name
32               ,data_type
33               ,data_length
34               ,data_scale
35               ,nullable
36               ,count(src1) cnt1
37               ,count(src2) cnt2
38         from ( select * from t1
39                union all
40                select * from t2
41              )
42         group by table_name
43               ,column_name
44               ,data_type
45               ,data_length
46               ,data_scale
47               ,nullable
48       )
49      ,similar_col as
50       ( select table_name
51               ,column_name
52               ,data_type
53               ,data_length
54               ,data_scale
55               ,nullable
56         from   src
57         where  cnt1 = cnt2
58       )
59      ,different_col as
60       ( select table_name
61               ,column_name
62               ,data_type
63               ,data_length
64               ,data_scale
65               ,nullable
66         from   src
67         where  cnt1 != cnt2
68       )
69      ,same as
70       ( select 'Same'   text
71               ,cast(null as varchar2(30)) owner
72               ,s.*
73        from    similar_col   s
74       )
75      ,diff1 as
76       ( select 'Diff' text
77               ,t1.owner
78               ,d.*
79         from   different_col d
80               ,t1
81         where  t1.table_name          = d.table_name
82         and    t1.column_name         = d.column_name
83         and    t1.data_type           = d.data_type
84         and    nvl(t1.data_length,-1) = nvl(d.data_length,-1)
85         and    nvl(t1.data_scale ,-1) = nvl(d.data_scale ,-1)
86         and    t1.nullable            = d.nullable
87       )
88      ,diff2 as
89       ( select 'Diff' text
90               ,t2.owner
91               ,d.*
92         from   different_col d
93               ,t2
94         where  t2.table_name          = d.table_name
95         and    t2.column_name         = d.column_name
96         and    t2.data_type           = d.data_type
97         and    nvl(t2.data_length,-1) = nvl(d.data_length,-1)
98         and    nvl(t2.data_scale ,-1) = nvl(d.data_scale ,-1)
99         and    t2.nullable            = d.nullable
100       )
101  select * from same
102  union all
103  select * from diff1
104  union all
105  select * from diff2
106  order by 1 desc,4
107  ;
 
TEXT OWNER      TABLE_NAME COLUMN_NAM DATA_TYPE  DATA_LENGTH DATA_SCALE N
Same            EMP        EMPNO      NUMBER              22          0 N
Same            EMP        SAL        NUMBER              22          0 Y
Diff CORE       EMP        DT         DATE                 7            N
Diff FLIP       EMP        DT         DATE                 7            Y
Diff FLIP       EMP        EMPNAME    VARCHAR2            19            N
Diff CORE       EMP        ENAME      VARCHAR2            20            Y
 
6 rows selected.To get the desired side by side output you would have to slightly modify the above and do a full outer join ... unfortunately, in 9.2.0.1.0, I got ORA-03113 trying to use the ANSI full outer join syntax ... to fake it with the traditional syntax ...
SQL> set lines 200 pages 500
SQL> with t1 as
  2       ( SELECT 1               src1
  3               ,to_number(null) src2
  4               ,owner
  5               ,table_name
  6               ,column_name
  7               ,data_type
  8               ,data_length
  9               ,data_scale
10               ,nullable
11         FROM  dba_tab_columns
12         WHERE owner      = 'CORE'
13         AND   table_name = 'EMP'
14       )
15      ,t2 as
16       ( SELECT to_number(null) src1
17               ,1               src2
18               ,owner
19               ,table_name
20               ,column_name
21               ,data_type
22               ,data_length
23               ,data_scale
24               ,nullable
25         FROM  dba_tab_columns
26         WHERE owner      = 'FLIP'
27         AND   table_name = 'EMP'
28       )
29      ,src as
30       ( select table_name
31               ,column_name
32               ,data_type
33               ,data_length
34               ,data_scale
35               ,nullable
36               ,count(src1) cnt1
37               ,count(src2) cnt2
38         from ( select * from t1
39                union all
40                select * from t2
41              )
42         group by table_name
43               ,column_name
44               ,data_type
45               ,data_length
46               ,data_scale
47               ,nullable
48       )
49      ,similar_col as
50       ( select table_name
51               ,column_name
52               ,data_type
53               ,data_length
54               ,data_scale
55               ,nullable
56         from   src
57         where  cnt1 = cnt2
58       )
59      ,different_col as
60       ( select table_name
61               ,column_name
62               ,data_type
63               ,data_length
64               ,data_scale
65               ,nullable
66         from   src
67         where  cnt1 != cnt2
68       )
69      ,sd1 as
70       ( select 'same' text
71               ,o.owner
72               ,s.*
73         from   similar_col   s
74               ,(select owner from t1 where rownum <2) o
75         union all
76         select 'diff' text
77               ,t1.owner
78               ,d.*
79         from   different_col d
80               ,t1
81         where  t1.table_name          = d.table_name
82         and    t1.column_name         = d.column_name
83         and    t1.data_type           = d.data_type
84         and    nvl(t1.data_length,-1) = nvl(d.data_length,-1)
85         and    nvl(t1.data_scale ,-1) = nvl(d.data_scale ,-1)
86         and    t1.nullable            = d.nullable
87       )
88      ,sd2 as
89       ( select 'same' text
90               ,o.owner
91               ,s.*
92         from   similar_col   s
93               ,(select owner from t2 where rownum <2) o
94         union all
95         select 'diff' text
96               ,t2.owner
97               ,d.*
98         from   different_col d
99               ,t2
100         where  t2.table_name          = d.table_name
101         and    t2.column_name         = d.column_name
102         and    t2.data_type           = d.data_type
103         and    nvl(t2.data_length,-1) = nvl(d.data_length,-1)
104         and    nvl(t2.data_scale ,-1) = nvl(d.data_scale ,-1)
105         and    t2.nullable            = d.nullable
106       )
107  select nvl(sd1.text,sd2.text) text
108        ,sd1.owner
109        ,sd1.table_name
110        ,sd1.column_name
111        ,sd1.data_type
112        ,sd1.data_length
113        ,sd1.data_scale
114        ,sd1.nullable
115        ,sd2.owner
116        ,sd2.table_name
117        ,sd2.column_name
118        ,sd2.data_type
119        ,sd2.data_length
120        ,sd2.data_scale
121        ,sd2.nullable
122  from  sd1,sd2
123  where sd1.table_name  = sd2.table_name  (+)
124  and   sd1.column_name = sd2.column_name (+)
125  union
126  select nvl(sd1.text,sd2.text) text
127        ,sd1.owner
128        ,sd1.table_name
129        ,sd1.column_name
130        ,sd1.data_type
131        ,sd1.data_length
132        ,sd1.data_scale
133        ,sd1.nullable
134        ,sd2.owner
135        ,sd2.table_name
136        ,sd2.column_name
137        ,sd2.data_type
138        ,sd2.data_length
139        ,sd2.data_scale
140        ,sd2.nullable
141  from  sd1,sd2
142  where sd1.table_name  (+) = sd2.table_name
143  and   sd1.column_name (+) = sd2.column_name
144  order by 1 desc nulls last, 4
145  ;
TEXT OWNER      TABLE_NAME COLUMN_NAM DATA_TYPE  DATA_LENGTH DATA_SCALE N OWNER      TABLE_NAME COLUMN_NAM DATA_TYPE  DATA_LENGTH DATA_SCALE N
same CORE       EMP        EMPNO      NUMBER              22          0 N FLIP       EMP        EMPNO      NUMBER              22          0 N
same CORE       EMP        SAL        NUMBER              22          0 Y FLIP       EMP        SAL        NUMBER              22          0 Y
diff CORE       EMP        DT         DATE                 7            N FLIP       EMP        DT         DATE                 7            Y
diff CORE       EMP        ENAME      VARCHAR2            20            Y
diff                                                                      FLIP       EMP        EMPNAME    VARCHAR2            19            NNow, having done all this ... was it worthwhile? Wouldn't comparing the output of dbms_metdata.get_ddl been as good (actionable) as this? Hmmm.
Cheers.