Merge pull request #358 from Deepak-Vohra/main

SQL-145 How to Fix Error 1064 When Using ALTER TABLE ADD CONSTRAINT in MySQL

Author: jzheaux

sql-queries-11/fix-error-1064-when-using-ALTER-TABLE-ADD CONSTRAINT-in-MySQL/drop-constraint.sql

@@ -0,0 +1,3 @@
+-- Drop the constraint so that we can add it back
+ALTER TABLE Specification 
+DROP FOREIGN KEY specification_program_id_fkey;

sql-queries-11/fix-error-1064-when-using-ALTER-TABLE-ADD CONSTRAINT-in-MySQL/example-sql-statements-that-generate-error-message.sql

@@ -0,0 +1,54 @@
+# Correct syntax
+ALTER TABLE Specification
+ADD CONSTRAINT specification_program_id_fkey 
+FOREIGN KEY (program_id)
+REFERENCES Program (id);
+
+# Incorrect syntax; jumbled syntax
+ALTER TABLE Specification
+ADD FOREIGN KEY specification_program_id_fkey 
+CONSTRAINT (program_id)
+REFERENCES Program (id);
+
+# Incorrect syntax; wrong punctuation
+ALTER TABLE Specification (
+ADD CONSTRAINT
+  specification_program_id_fkey 
+  FOREIGN KEY (program_id)
+  REFERENCES Program (id)
+);
+
+# Incorrect syntax; a reserved word
+ALTER TABLE Specification
+ADD CONSTRAINT foreign 
+FOREIGN KEY (program_id)
+REFERENCES Program (id);
+
+# Incorrect syntax, misspelled keyword REFERENCES
+ALTER TABLE Specification
+ADD CONSTRAINT specification_program_id_fkey 
+FOREIGN KEY (program_id)
+REFERENCE Program (id);
+
+# Incorrect syntax, missing closing parenthesis
+ALTER TABLE Specification
+ADD CONSTRAINT specification_program_id_fkey 
+FOREIGN KEY (program_id
+REFERENCES Program (id);
+
+# Incorrect syntax; quotes
+ALTER TABLE "Specification"
+ADD CONSTRAINT "specification_program_id_fkey" 
+FOREIGN KEY ("program_id")
+REFERENCES Program ("id");
+
+# Correct syntax; backticks
+ALTER TABLE `Specification`
+ADD CONSTRAINT `specification_program_id_fkey` 
+FOREIGN KEY (`program_id`)
+REFERENCES Program (`id`);
+
+# Incorrect syntax, missing required elements
+ALTER TABLE Specification
+ADD CONSTRAINT specification_program_id_fkey
+FOREIGN KEY (program_id);

sql-queries-11/fix-error-1064-when-using-ALTER-TABLE-ADD CONSTRAINT-in-MySQL/list-constraint.sql

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+# List the FK constraints that reference the PROGRAM table 
+SELECT 
+  TABLE_NAME, COLUMN_NAME, CONSTRAINT_NAME, REFERENCED_TABLE_NAME, REFERENCED_COLUMN_NAME
+FROM
+  INFORMATION_SCHEMA.KEY_COLUMN_USAGE
+WHERE
+  REFERENCED_TABLE_SCHEMA = (SELECT DATABASE()) AND
+  REFERENCED_TABLE_NAME = 'PROGRAM' \G