ndlli 发表于 2018-10-1 11:26:40

获取MySQL5.5表元信息

CREATE    FUNCTION `get_tab_ddl`(p_tab_name VARCHAR(100)) RETURNS text  NO SQL
  DETERMINISTIC
  BEGIN
  DECLARE v_return TEXT DEFAULT '';
  DECLARE v_ddl TEXT DEFAULT '';
  #表信息相关变量
  DECLARE v_engine VARCHAR(255);
  DECLARE v_row_format VARCHAR(255);
  DECLARE v_tab_comment VARCHAR(255);
  #约束相关变量
  DECLARE v_cons_name VARCHAR(255);
  DECLARE v_cons_type VARCHAR(255);
  #约束列相关变量
  DECLARE v_cons_col_name VARCHAR(255);
  DECLARE v_ref_tab_schema VARCHAR(255);
  DECLARE v_ref_tab_name VARCHAR(255);
  DECLARE v_ref_col_name VARCHAR(255);
  DECLARE v_update_rule    VARCHAR(255);
  DECLARE v_delete_rule    VARCHAR(255);
  #索引相关变更
  DECLARE v_index_name VARCHAR(255);
  DECLARE v_l_index_name VARCHAR(255) DEFAULT '';
  DECLARE v_ind_col_name VARCHAR(255);
  DECLARE v_done INT DEFAULT 0;
  #列游标
  DECLARE cur_column CURSOR FOR
  SELECT CONCAT('    ','`',t.column_name,'` ',column_type,
  IF(t.is_nullable = 'NO',' NOT NULL',''),
  IF(t.extra IS NULL,'',CONCAT(' ',t.extra)),
  IF(t.column_default IS NULL,'',CONCAT(' ','DEFAULT ' , "'" , t.column_default , "'")),
  IF(t.column_comment = '','',CONCAT(' ','COMMENT ' , "'" , t.column_comment , "'")),',') tab_column
  FROM information_schema.columns t
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name
  ORDER BY t.ordinal_position;
  #主键约束
  DECLARE cur_pk CURSOR FOR
  SELECT t.column_name
  FROM information_schema.key_column_usage t
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name
  AND t.constraint_name = 'PRIMARY'
  ORDER BY t.ordinal_position;
  #其它约束游标
  DECLARE cur_cons CURSOR FOR
  SELECT t.constraint_type,t.constraint_name
  FROM information_schema.table_constraints t
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name
  AND t.constraint_type'PRIMARY KEY';
  #约束列游标
  DECLARE cur_col_cons CURSOR FOR
  SELECT t.column_name,t.referenced_table_schema,t.referenced_table_name,t.referenced_column_name,c.update_rule,c.delete_rule
  FROM information_schema.key_column_usage t
  LEFT JOIN information_schema.referential_constraints c ON (t.table_name = c.table_name AND t.constraint_name = c.constraint_name)
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name
  AND t.constraint_name = v_cons_name
  ORDER BY t.ordinal_position;
  #表上索引游标
  DECLARE cur_index CURSOR FOR
  SELECT t.index_name,t.column_name
  FROM information_schema.statistics t
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name
  AND NOT EXISTS (SELECT 1 FROM information_schema.table_constraints c
  WHERE t.table_schema = c.table_schema
  AND t.table_name = c.table_name
  AND t.index_name = c.constraint_name)
  ORDER BY t.index_name,t.seq_in_index;
  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET v_done=1;
  #表信息
  SELECT IF(t.engine = '' OR t.engine IS NULL,'',CONCAT(' ENGINE=',t.engine)) ENGINE,
  t.row_format,
  IF(t.table_comment = '' OR t.table_comment IS NULL,'',CONCAT(" COMMENT='",t.table_comment,"'")) table_comment
  INTO v_engine,v_row_format,v_tab_comment
  FROM information_schema.tables t
  WHERE t.table_schema = SCHEMA()
  AND t.table_name = p_tab_name;
  SET v_return = CONCAT('CREATE TABLE `',p_tab_name,'` (',CHAR(13));
  #打开列游标
  OPEN cur_column;
  FETCH cur_column INTO v_ddl;
  WHILE v_done1 DO
  SET v_return = CONCAT(v_return,v_ddl,CHAR(13));
  FETCH cur_column INTO v_ddl;
  END WHILE;
  CLOSE cur_column;
  SET v_ddl = '';
  #打开主键约束
  SET v_done = 0;
  OPEN cur_pk ;
  FETCH cur_pk INTO v_cons_col_name;
  WHILE v_done1 DO
  SET v_ddl = CONCAT(v_ddl,'`',v_cons_col_name,'`,');
  FETCH cur_pk INTO v_cons_col_name;
  END WHILE;
  CLOSE cur_pk;
  IF v_ddl'' THEN
  SET v_return = CONCAT(v_return,'    ','PRIMARY KEY (',LEFT(v_ddl,CHAR_LENGTH(v_ddl) - 1),'),',CHAR(13));
  END IF;
  SET v_return = CONCAT(LEFT(v_return,CHAR_LENGTH(v_return) - 2),CHAR(13));
  SET v_return = CONCAT(v_return,') ',v_engine,v_tab_comment,' ;',CHAR(13));
  #打开其它约束游标
  SET v_done = 0;
  OPEN cur_cons;
  FETCH cur_cons INTO v_cons_type,v_cons_name;
  WHILE v_done1 DO
  IF v_cons_type = 'FOREIGN KEY' THEN
  SET v_return = CONCAT(v_return,CHAR(13),'ALTER TABLE `',p_tab_name,'` ADD CONSTRAINT `',v_cons_name,'` FOREIGN KEY (');
  #打开外键约束列游标
  OPEN cur_col_cons;
  FETCH cur_col_cons INTO v_cons_col_name,v_ref_tab_schema,v_ref_tab_name,v_ref_col_name,v_update_rule ,v_delete_rule;
  WHILE v_done1 DO
  SET v_return = CONCAT(v_return,'`',v_cons_col_name,'`) REFERENCES `',v_ref_tab_name,'` (`',v_ref_col_name,'`) ',
  'ON DELETE ',v_delete_rule,' ON UPDATE ',v_update_rule);
  FETCH cur_col_cons INTO v_cons_col_name,v_ref_tab_schema,v_ref_tab_name,v_ref_col_name,v_update_rule ,v_delete_rule;
  END WHILE;
  CLOSE cur_col_cons;
  SET v_return = CONCAT(v_return,';',CHAR(13));
  ELSE
  SET v_return = CONCAT(v_return,CHAR(13),'ALTER TABLE `',p_tab_name,'` ADD CONSTRAINT `',v_cons_name,'` UNQINE (');
  #打开唯一约束列游标
  OPEN cur_col_cons;
  FETCH cur_col_cons INTO v_cons_col_name,v_ref_tab_schema,v_ref_tab_name,v_ref_col_name,v_update_rule ,v_delete_rule;
  WHILE v_done1 DO
  SET v_return = CONCAT(v_return,'`',v_cons_col_name,'`,');
  FETCH cur_col_cons INTO v_cons_col_name,v_ref_tab_schema,v_ref_tab_name,v_ref_col_name,v_update_rule ,v_delete_rule;
  END WHILE;
  CLOSE cur_col_cons;
  SET v_return = CONCAT(LEFT(v_return,CHAR_LENGTH(v_return) - 1),');',CHAR(13));
  END IF;
  SET v_done = 0;
  FETCH cur_cons INTO v_cons_type,v_cons_name;
  END WHILE;
  CLOSE cur_cons;
  #打开索引游标
  SET v_done = 0;
  SET v_ddl = '';
  OPEN cur_index;
  FETCH cur_index INTO v_index_name,v_ind_col_name;
  WHILE v_done1 DO
  IF v_index_name = v_l_index_name THEN
  SET v_ddl = CONCAT(v_ddl,'`',v_ind_col_name,'`,');
  ELSEIF v_l_index_name IS NULL OR v_l_index_name = '' THEN
  SET v_ddl = CONCAT(v_ddl,CHAR(13),'CREATE INDEX `',v_index_name,'` ON `',p_tab_name,'` (`',v_ind_col_name,'`,');
  ELSE
  SET v_ddl = CONCAT(LEFT(v_ddl,CHAR_LENGTH(v_ddl) - 1),');',CHAR(13),CHAR(13),'CREATE INDEX `',
  v_index_name,'` ON `',p_tab_name,'` (`',v_ind_col_name,'`,');
  END IF;
  SET v_l_index_name = v_index_name;
  FETCH cur_index INTO v_index_name,v_ind_col_name;
  END WHILE;
  CLOSE cur_index;
  IF v_ddl'' THEN
  SET v_return = CONCAT(v_return,LEFT(v_ddl,CHAR_LENGTH(v_ddl) - 1),');',CHAR(13));
  END IF;
  RETURN v_return;
  END

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