Refactor database schemas and update related tests

- Refactor database schema by renaming `t1_2` to `col_1` across multiple tables.
- Update foreign key constraints to ensure integrity with the new column name.
- Adjust test cases to verify the correctness of the updated SQL statements.

Signed-off-by: katsumata <12413150+winor30@users.noreply.github.com>

Author: winor30

internal/hammer/diff_test.go

@@ -1045,7 +1045,7 @@ CREATE TABLE t2 (
 			from: `
 CREATE TABLE t1 (
   t1_1 INT64 NOT NULL,
-  t1_2 INT64,
+  col_1 INT64,
 ) PRIMARY KEY(t1_1);
 
 CREATE TABLE t2 (
@@ -1054,8 +1054,8 @@ CREATE TABLE t2 (
 
 CREATE TABLE t3 (
   t3_1 INT64 NOT NULL,
-  t1_2 INT64,
-  CONSTRAINT FK_t3 FOREIGN KEY (t1_2) REFERENCES t2 (t2_1),
+  col_1 INT64,
+  CONSTRAINT FK_t3 FOREIGN KEY (col_1) REFERENCES t2 (t2_1),
 ) PRIMARY KEY(t3_1);
 		`,
 			to: `
@@ -1069,30 +1069,30 @@ CREATE TABLE t2 (
 
 CREATE TABLE t3 (
   t3_1 INT64 NOT NULL,
-  t1_2 INT64,
-  CONSTRAINT FK_t3 FOREIGN KEY (t1_2) REFERENCES t2 (t2_1),
+  col_1 INT64,
+  CONSTRAINT FK_t3 FOREIGN KEY (col_1) REFERENCES t2 (t2_1),
 ) PRIMARY KEY(t3_1);
 		`,
 			expected: []string{
-				`ALTER TABLE t1 DROP COLUMN t1_2`,
+				`ALTER TABLE t1 DROP COLUMN col_1`,
 			},
 		},
 		{
 			name: "Do not drop unrelated constraint (same referenced column name)",
 			from: `
 CREATE TABLE t1 (
   t1_1 INT64 NOT NULL,
-  t1_2 INT64,
+  col_1 INT64,
 ) PRIMARY KEY(t1_1);
 
 CREATE TABLE t2 (
-  t1_2 INT64 NOT NULL,
-) PRIMARY KEY(t1_2);
+  col_1 INT64 NOT NULL,
+) PRIMARY KEY(col_1);
 
 CREATE TABLE t3 (
   t3_1 INT64 NOT NULL,
-  t1_2 INT64,
-  CONSTRAINT FK_t3 FOREIGN KEY (t1_2) REFERENCES t2 (t1_2),
+  t3_2 INT64,
+  CONSTRAINT FK_t3 FOREIGN KEY (t3_2) REFERENCES t2 (col_1),
 ) PRIMARY KEY(t3_1);
 		`,
 			to: `
@@ -1101,17 +1101,17 @@ CREATE TABLE t1 (
 ) PRIMARY KEY(t1_1);
 
 CREATE TABLE t2 (
-  t1_2 INT64 NOT NULL,
-) PRIMARY KEY(t1_2);
+  col_1 INT64 NOT NULL,
+) PRIMARY KEY(col_1);
 
 CREATE TABLE t3 (
   t3_1 INT64 NOT NULL,
-  t1_2 INT64,
-  CONSTRAINT FK_t3 FOREIGN KEY (t1_2) REFERENCES t2 (t1_2),
+  t3_2 INT64,
+  CONSTRAINT FK_t3 FOREIGN KEY (t3_2) REFERENCES t2 (col_1),
 ) PRIMARY KEY(t3_1);
 		`,
 			expected: []string{
-				`ALTER TABLE t1 DROP COLUMN t1_2`,
+				`ALTER TABLE t1 DROP COLUMN col_1`,
 			},
 		},
 		{