pub struct TableAlterStatement { /* private fields */ }
Expand description

Alter a table

Examples

use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .add_column(
        ColumnDef::new(Alias::new("new_col"))
            .integer()
            .not_null()
            .default(100),
    )
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` ADD COLUMN `new_col` int NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN "new_col" integer NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(SqliteQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN "new_col" integer NOT NULL DEFAULT 100"#,
);

Implementationsยง

Construct alter table statement

Set table name

Add a column to an existing table

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .add_column(
        ColumnDef::new(Alias::new("new_col"))
            .integer()
            .not_null()
            .default(100),
    )
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` ADD COLUMN `new_col` int NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN "new_col" integer NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(SqliteQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN "new_col" integer NOT NULL DEFAULT 100"#,
);

Try add a column to an existing table if it does not exists

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .add_column_if_not_exists(
        ColumnDef::new(Alias::new("new_col"))
            .integer()
            .not_null()
            .default(100),
    )
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` ADD COLUMN IF NOT EXISTS `new_col` int NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN IF NOT EXISTS "new_col" integer NOT NULL DEFAULT 100"#
);
assert_eq!(
    table.to_string(SqliteQueryBuilder),
    r#"ALTER TABLE "font" ADD COLUMN "new_col" integer NOT NULL DEFAULT 100"#,
);

Modify a column in an existing table

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .modify_column(
        ColumnDef::new(Alias::new("new_col"))
            .big_integer()
            .default(999),
    )
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` MODIFY COLUMN `new_col` bigint DEFAULT 999"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    [
        r#"ALTER TABLE "font""#,
        r#"ALTER COLUMN "new_col" TYPE bigint,"#,
        r#"ALTER COLUMN "new_col" SET DEFAULT 999"#,
    ]
    .join(" ")
);
// Sqlite not support modifying table column

Rename a column in an existing table

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .rename_column(Alias::new("new_col"), Alias::new("new_column"))
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` RENAME COLUMN `new_col` TO `new_column`"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    r#"ALTER TABLE "font" RENAME COLUMN "new_col" TO "new_column""#
);
assert_eq!(
    table.to_string(SqliteQueryBuilder),
    r#"ALTER TABLE "font" RENAME COLUMN "new_col" TO "new_column""#
);

Drop a column from an existing table

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Font::Table)
    .drop_column(Alias::new("new_column"))
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    r#"ALTER TABLE `font` DROP COLUMN `new_column`"#
);
assert_eq!(
    table.to_string(PostgresQueryBuilder),
    r#"ALTER TABLE "font" DROP COLUMN "new_column""#
);
assert_eq!(
    table.to_string(SqliteQueryBuilder),
    r#"ALTER TABLE "font" DROP COLUMN "new_column""#
);

Add a foreign key to existing table

Examples
use sea_query::{tests_cfg::*, *};

let foreign_key_char = TableForeignKey::new()
    .name("FK_character_glyph")
    .from_tbl(Char::Table)
    .from_col(Char::FontId)
    .from_col(Char::Id)
    .to_tbl(Glyph::Table)
    .to_col(Char::FontId)
    .to_col(Char::Id)
    .on_delete(ForeignKeyAction::Cascade)
    .on_update(ForeignKeyAction::Cascade)
    .to_owned();

let foreign_key_font = TableForeignKey::new()
    .name("FK_character_font")
    .from_tbl(Char::Table)
    .from_col(Char::FontId)
    .to_tbl(Font::Table)
    .to_col(Font::Id)
    .on_delete(ForeignKeyAction::Cascade)
    .on_update(ForeignKeyAction::Cascade)
    .to_owned();

let table = Table::alter()
    .table(Character::Table)
    .add_foreign_key(&foreign_key_char)
    .add_foreign_key(&foreign_key_font)
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    [
        r#"ALTER TABLE `character`"#,
        r#"ADD CONSTRAINT `FK_character_glyph`"#,
        r#"FOREIGN KEY (`font_id`, `id`) REFERENCES `glyph` (`font_id`, `id`)"#,
        r#"ON DELETE CASCADE ON UPDATE CASCADE,"#,
        r#"ADD CONSTRAINT `FK_character_font`"#,
        r#"FOREIGN KEY (`font_id`) REFERENCES `font` (`id`)"#,
        r#"ON DELETE CASCADE ON UPDATE CASCADE"#,
    ]
    .join(" ")
);

assert_eq!(
    table.to_string(PostgresQueryBuilder),
    [
        r#"ALTER TABLE "character""#,
        r#"ADD CONSTRAINT "FK_character_glyph""#,
        r#"FOREIGN KEY ("font_id", "id") REFERENCES "glyph" ("font_id", "id")"#,
        r#"ON DELETE CASCADE ON UPDATE CASCADE,"#,
        r#"ADD CONSTRAINT "FK_character_font""#,
        r#"FOREIGN KEY ("font_id") REFERENCES "font" ("id")"#,
        r#"ON DELETE CASCADE ON UPDATE CASCADE"#,
    ]
    .join(" ")
);

// Sqlite not support modifying table column

Drop a foreign key from existing table

Examples
use sea_query::{tests_cfg::*, *};

let table = Table::alter()
    .table(Character::Table)
    .drop_foreign_key(Alias::new("FK_character_glyph"))
    .drop_foreign_key(Alias::new("FK_character_font"))
    .to_owned();

assert_eq!(
    table.to_string(MysqlQueryBuilder),
    [
        r#"ALTER TABLE `character`"#,
        r#"DROP FOREIGN KEY `FK_character_glyph`,"#,
        r#"DROP FOREIGN KEY `FK_character_font`"#,
    ]
    .join(" ")
);

assert_eq!(
    table.to_string(PostgresQueryBuilder),
    [
        r#"ALTER TABLE "character""#,
        r#"DROP CONSTRAINT "FK_character_glyph","#,
        r#"DROP CONSTRAINT "FK_character_font""#,
    ]
    .join(" ")
);

// Sqlite not support modifying table column

Trait Implementationsยง

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Returns the โ€œdefault valueโ€ for a type. Read more
Build corresponding SQL statement for certain database backend and return SQL string
Build corresponding SQL statement for certain database backend and return SQL string
Build corresponding SQL statement for certain database backend and return SQL string

Auto Trait Implementationsยง

Blanket Implementationsยง

Gets the TypeId of self. Read more
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Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
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Performs the conversion.