从复合外键对子集进行级联更新

Question

我有下面发布的表。如图所示，表GridCell 的所有行都作为复合主键，它们是表GridCellOpDependentParticular 中的外键。这同样适用于表OpDependentParticular。 对于表GridCell，geometryOfCellRepresentativeToTreatment 和geometryOfCellRepresentativeToBuffer 两列的初始值设置为POLYGON EMPTY 或010300000000000000。 创建表后，我将更新后两列如下：

sql = '''
        UPDATE GridCell set 
            geometryOfCellRepresentativeToTreatment = ST_GeomFromGeoJSON(fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON)
        WHERE 
            geometryOfCellRepresentativeToTreatment = 'POLYGON EMPTY' and fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON <> '' and fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON IS NOT NULL;

        UPDATE GridCell SET
            geometryOfCellRepresentativeToBuffer = ST_GeomFromGeoJSON(fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON)
        WHERE 
           geometryOfCellRepresentativeToBuffer = 'POLYGON EMPTY' and fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON <> '' and fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON IS NOT NULL;
        '''.format()
    self.cur.execute(sql)
    self.conn.commit()

我想要实现的是使表GridCellOpDependentParticular 中的两列fk_gridCell_geometryOfCellRepresentativeToTreatment geometry 和fk_gridCell_geometryOfCellRepresentativeToBuffer geometry 在我执行后自动更新 上述更新语句。

我搜索了答案，但没有找到仅更新复合外键中的某些列而不指定所有外键的答案

代码：

create table if not exists GridCell(
    fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON jsonb,
    fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON jsonb,
    geometryOfCellRepresentativeToTreatment geometry,
    geometryOfCellRepresentativeToBuffer geometry,
    fk_site_selectedSiteID text,
    fk_OpIndependentParticular_isTreatment boolean,
    fk_OpIndependentParticular_isBuffer boolean,
    fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge float8,
    fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge float8,
    foreign key (fk_site_selectedSiteID) references Site(selectedSiteID),
    foreign key (fk_OpIndependentParticular_isTreatment,fk_OpIndependentParticular_isBuffer,fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge,fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge) 
        references OpIndependentParticular(isTreatment,isBuffer,distanceFromCPOfTreatmentToNearestEdge,distanceFromCPOfBufferToNearestEdge),
    primary key (fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,geometryOfCellRepresentativeToTreatment,
    geometryOfCellRepresentativeToBuffer,fk_site_selectedSiteID,fk_OpIndependentParticular_isTreatment,fk_OpIndependentParticular_isBuffer,fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge,
    fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge)
    /*
     * UNIQUE (fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,geometryOfCellRepresentativeToTreatment,geometryOfCellRepresentativeToBuffer),
     * UNIQUE (fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,geometryOfCellRepresentativeToTreatment,geometryOfCellRepresentativeToBuffer,fk_site_selectedSiteID),
     * */
)
create table if not exists OpDependentParticular(
    AoCForCellsRepresentativeToTreatment float8,
    AoCForCellsRepresentativeToBuffer float8,
    AvgHPerWindowRepresentativeToTreatment float8,
    AvgHPerWindowRepresentativeToBuffer float8,
    primary key(AoCForCellsRepresentativeToTreatment,AoCForCellsRepresentativeToBuffer,AvgHPerWindowRepresentativeToTreatment,
    AvgHPerWindowRepresentativeToBuffer)
)
create table if not exists GridCellOpDependentParticular(
    fk_gridCell_fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON jsonb,
    fk_gridCell_fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON jsonb,
    fk_gridCell_geometryOfCellRepresentativeToTreatment geometry,
    fk_gridCell_geometryOfCellRepresentativeToBuffer geometry,
    fk_gridCell_fk_site_selectedSiteID text,
    fk_gridCell_fk_OpIndependentParticular_isTreatment boolean,
    fk_gridCell_fk_OpIndependentParticular_isBuffer boolean,
    fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge float8,
    fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge float8,
    foreign key (fk_gridCell_fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,fk_gridCell_fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,
    fk_gridCell_geometryOfCellRepresentativeToTreatment,fk_gridCell_geometryOfCellRepresentativeToBuffer,fk_gridCell_fk_site_selectedSiteID,
    fk_gridCell_fk_OpIndependentParticular_isTreatment,fk_gridCell_fk_OpIndependentParticular_isBuffer,fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge,
    fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge) references GridCell(fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,
    fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,geometryOfCellRepresentativeToTreatment,geometryOfCellRepresentativeToBuffer,fk_site_selectedSiteID,fk_OpIndependentParticular_isTreatment,
    fk_OpIndependentParticular_isBuffer,fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge,fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge),
    
    fk_OpDependentParticular_AoCForCellsRepresentativeToTreatment float8,
    fk_OpDependentParticular_AoCForCellsRepresentativeToBuffer float8,
    fk_OpDependentParticular_AvgHPerWindowRepresentativeToTreatment float8,
    fk_OpDependentParticular_AvgHPerWindowRepresentativeToBuffer float8,
    foreign key (fk_OpDependentParticular_AoCForCellsRepresentativeToTreatment,fk_OpDependentParticular_AoCForCellsRepresentativeToBuffer,
    fk_OpDependentParticular_AvgHPerWindowRepresentativeToTreatment,fk_OpDependentParticular_AvgHPerWindowRepresentativeToBuffer) references OpDependentParticular(
    AoCForCellsRepresentativeToTreatment,AoCForCellsRepresentativeToBuffer,AvgHPerWindowRepresentativeToTreatment,AvgHPerWindowRepresentativeToBuffer),
    
    primary key (fk_gridCell_fourCornersOfKeyWindowRepresentativeToTreatmentAsGeoJSON,fk_gridCell_fourCornersOfKeyWindowRepresentativeToBufferAsGeoJSON,
    fk_gridCell_geometryOfCellRepresentativeToTreatment,fk_gridCell_geometryOfCellRepresentativeToBuffer,fk_gridCell_fk_site_selectedSiteID,fk_gridCell_fk_OpIndependentParticular_isTreatment,
    fk_gridCell_fk_OpIndependentParticular_isBuffer,fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfTreatmentToNearestEdge,
    fk_gridCell_fk_OpIndependentParticular_distanceFromCPOfBufferToNearestEdge,fk_OpDependentParticular_AoCForCellsRepresentativeToTreatment,fk_OpDependentParticular_AoCForCellsRepresentativeToBuffer,
    fk_OpDependentParticular_AvgHPerWindowRepresentativeToTreatment,fk_OpDependentParticular_AvgHPerWindowRepresentativeToBuffer)
);

Answer 1

您要查找的是FOREIGN KEY ... ON UPDATE CASCADE。考虑这个表t1，记录如下：

CREATE TABLE t1 (
  gid int,
  geom geometry(point,4326) DEFAULT 'POINT EMPTY',
  PRIMARY KEY (gid,geom)
);

INSERT INTO t1 VALUES (42,'POINT(1 1)');

现在在表t2 上创建一个外键，但这次将其声明为ON UPDATE CASCADE：

CREATE TABLE t2 (
  gid int PRIMARY KEY,
  t1_gid int,
  t1_geom geometry(point,4326),
  FOREIGN KEY (t1_gid,t1_geom) 
    REFERENCES t1 (gid,geom)
    ON UPDATE CASCADE
);

INSERT INTO t2 VALUES (0,42,'POINT(1 1)');

现在，如果您更改 t1 上的复合主键（或其一部分）的值 ...

UPDATE t1 SET gid = 1
WHERE gid = 42;

...它会直接反映在t2:

SELECT gid,t1_gid,ST_AsText(t1_geom) FROM t2;

 gid | t1_gid | st_astext  
-----+--------+------------
   0 |      1 | POINT(1 1)

演示：db<>fiddle