forked from docs/doc-exports
Lu, Huayi
27019c2991
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com> Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
87 lines
5.0 KiB
HTML
87 lines
5.0 KiB
HTML
<a name="EN-US_TOPIC_0000001819336221"></a><a name="EN-US_TOPIC_0000001819336221"></a>
|
|
|
|
<h1 class="topictitle1">Adding/Deleting a Column</h1>
|
|
<div id="body8662426"><p id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_p7574545962">The statements for adding and deleting columns in MySQL are different from those in GaussDB(DWS). DSC will perform adaptation based on GaussDB(DWS) features during migration.</p>
|
|
<div class="caution" id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_note9749104517138"><span class="cautiontitle"><img src="public_sys-resources/caution_3.0-en-us.png"> </span><div class="cautionbody"><p id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_p117497455133">GaussDB does not support the update of sequence numbers in table definitions. Temporarily, Migration Tool does not support the complete migration of the <cf id="Bold">FRIST</cf> and <cf id="Bold">AFTER</cf> features. So as a workaround, it simply deletes the keyword.</p>
|
|
</div></div>
|
|
<p id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_p8822521203711"><strong id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_b20727929204011">Input</strong></p>
|
|
<pre class="screen" id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_screen832116160817">CREATE TABLE IF NOT EXISTS `runoob_alter_test`(
|
|
`dataType1` int NOT NULL AUTO_INCREMENT,
|
|
`dataType2` FLOAT(10,2),
|
|
`dataType3` DOUBLE(20,8),
|
|
`dataType4` TEXT NOT NULL,
|
|
`dataType5` YEAR NOT NULL DEFAULT '2018',
|
|
`dataType6` DATETIME NOT NULL DEFAULT '2018-10-12 15:27:33.999999',
|
|
`dataType7` CHAR NOT NULL DEFAULT '',
|
|
`dataType8` VARCHAR(50),
|
|
`dataType9` VARCHAR(50) NOT NULL DEFAULT '',
|
|
`dataType10` TIME NOT NULL DEFAULT '10:20:59',
|
|
PRIMARY KEY(`dataType1`)
|
|
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
|
|
|
|
## A.
|
|
ALTER TABLE runoob_alter_test ADD dataType1_1 INT NOT NULL AFTER dataType1;
|
|
ALTER TABLE runoob_alter_test DROP dataType1_1;
|
|
|
|
## B.
|
|
ALTER TABLE runoob_alter_test ADD dataType1_1 INT NOT NULL FIRST;
|
|
ALTER TABLE runoob_alter_test DROP dataType1_1;
|
|
|
|
## C.
|
|
ALTER TABLE runoob_alter_test ADD COLUMN dataType1_1 INT NOT NULL AFTER dataType2;
|
|
ALTER TABLE runoob_alter_test DROP COLUMN dataType1_1;
|
|
|
|
## D.
|
|
ALTER TABLE runoob_alter_test ADD COLUMN dataType1_1 INT NOT NULL FIRST;
|
|
ALTER TABLE runoob_alter_test DROP COLUMN dataType1_1;
|
|
|
|
## E.
|
|
ALTER TABLE runoob_alter_test ADD COLUMN(dataType1_1 INT NOT NULL, dataType1_2 VARCHAR(200) NOT NULL);
|
|
ALTER TABLE runoob_alter_test DROP COLUMN dataType1_1, DROP COLUMN dataType1_2;
|
|
</pre>
|
|
<p id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_p1431826173714"><strong id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_b11199142516406">Output</strong></p>
|
|
<pre class="screen" id="EN-US_TOPIC_0000001819336221__en-us_topic_0000001658024790_en-us_topic_0000001436055765_en-us_topic_0214164714_screen14391919489">CREATE TABLE "public"."runoob_alter_test"
|
|
(
|
|
"datatype1" SERIAL NOT NULL,
|
|
"datatype2" REAL,
|
|
"datatype3" DOUBLE PRECISION,
|
|
"datatype4" TEXT NOT NULL,
|
|
"datatype5" SMALLINT NOT NULL DEFAULT '2018',
|
|
"datatype6" TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT '2018-10-12 15:27:33.999999',
|
|
"datatype7" CHAR(4) NOT NULL DEFAULT '',
|
|
"datatype8" VARCHAR(200),
|
|
"datatype9" VARCHAR(200) NOT NULL DEFAULT '',
|
|
"datatype10" TIME WITHOUT TIME ZONE NOT NULL DEFAULT '10:20:59',
|
|
PRIMARY KEY ("datatype1")
|
|
)
|
|
WITH ( ORIENTATION = ROW, COMPRESSION = NO )
|
|
NOCOMPRESS
|
|
DISTRIBUTE BY HASH ("datatype1");
|
|
|
|
-- A.
|
|
ALTER TABLE "public"."runoob_alter_test" ADD COLUMN "datatype1_1" INTEGER NOT NULL DEFAULT 0;
|
|
ALTER TABLE "public"."runoob_alter_test" DROP COLUMN "datatype1_1" RESTRICT;
|
|
|
|
-- B.
|
|
ALTER TABLE "public"."runoob_alter_test" ADD COLUMN "datatype1_1" INTEGER NOT NULL DEFAULT 0;
|
|
ALTER TABLE "public"."runoob_alter_test" DROP COLUMN "datatype1_1" RESTRICT;
|
|
|
|
-- C.
|
|
ALTER TABLE "public"."runoob_alter_test" ADD COLUMN "datatype1_1" INTEGER NOT NULL DEFAULT 0;
|
|
ALTER TABLE "public"."runoob_alter_test" DROP COLUMN "datatype1_1" RESTRICT;
|
|
|
|
-- D.
|
|
ALTER TABLE "public"."runoob_alter_test" ADD COLUMN "datatype1_1" INTEGER NOT NULL DEFAULT 0;
|
|
ALTER TABLE "public"."runoob_alter_test" DROP COLUMN "datatype1_1" RESTRICT;
|
|
|
|
-- E.
|
|
ALTER TABLE "public"."runoob_alter_test" ADD COLUMN "datatype1_1" INTEGER NOT NULL, ADD COLUMN "datatype1_2" VARCHAR(800) NOT NULL DEFAULT '';
|
|
ALTER TABLE "public"."runoob_alter_test" DROP COLUMN "datatype1_1" RESTRICT, DROP COLUMN "datatype1_2" RESTRICT;</pre>
|
|
</div>
|
|
<div>
|
|
<div class="familylinks">
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_16_0119.html">Table (Optional Parameters and Operations)</a></div>
|
|
</div>
|
|
</div>
|
|
|