Help Center/ GaussDB(DWS)/ Tool Guide/ DSC/ SQL Syntax Migration Reference/ MySQL Syntax Migrating/ Schema Objects and Data Definition Language (DDL)/ Table (Optional Parameters and Operations)/ COMMENT
Updated on 2024-07-19 GMT+08:00
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COMMENT

In MySQL, COMMENT is a comment for a table. In GaussDB(DWS), this attribute can be used to modify table definition. During migration using DSC, additional table attribute information is added.

Input

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CREATE TABLE `public`.`runoob_alter_test`(
    `dataType1` int NOT NULL AUTO_INCREMENT,
`dataType2` FLOAT (10,2) COMMENT'dataType2 column',
    PRIMARY KEY(`dataType1`)
) comment='table comment'; 

ALTER TABLE `public`.`runoob_alter_test` COMMENT 'table comment after modification';
ALTER TABLE `public`.`runoob_alter_test` ADD INDEX age_index(dataType2) COMMENT' index';

Output

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CREATE TABLE "public"."runoob_alter_test"
(
  "datatype1" SERIAL NOT NULL,
"datatype2" REAL COMMENT 'dataType2 column',
  PRIMARY KEY ("datatype1")
)
  WITH ( ORIENTATION = ROW, COMPRESSION = NO )
  NOCOMPRESS
  DISTRIBUTE BY HASH ("datatype1")
COMMENT 'Comment of the table';
ALTER TABLE `public`.`runoob_alter_test` COMMENT 'table comment after modification';
CREATE INDEX "age_index" ON "public"."runoob_alter_test" ("dataType2") COMMENT' index';