com.alibaba.druid.stat.TableStat.Column Java Examples

@Override
protected Column getColumn(SQLExpr expr) {
    if (aliasMap == null) {
        return null;
    }

    if (expr instanceof SQLPropertyExpr) {
        return getColumnByExpr((SQLPropertyExpr) expr);
    }

    if (expr instanceof SQLIdentifierExpr) {
        return getColumnByExpr((SQLIdentifierExpr) expr);
    }

    if (expr instanceof SQLBetweenExpr) {
        return getColumnByExpr((SQLBetweenExpr) expr);
    }
    return null;
}
 

private Column getColumnByExpr(SQLBetweenExpr betweenExpr) {
    if (betweenExpr.getTestExpr() != null) {
        String tableName = null;
        String column = null;
        if (betweenExpr.getTestExpr() instanceof SQLPropertyExpr) { //field has alias
            tableName = ((SQLIdentifierExpr) ((SQLPropertyExpr) betweenExpr.getTestExpr()).getOwner()).getName();
            column = ((SQLPropertyExpr) betweenExpr.getTestExpr()).getName();
        } else if (betweenExpr.getTestExpr() instanceof SQLIdentifierExpr) {
            column = ((SQLIdentifierExpr) betweenExpr.getTestExpr()).getName();
            tableName = getOwnerTableName(betweenExpr, column);
        }
        if (tableName != null && !"".equals(tableName)) {
            checkAliasInColumn(tableName, false);
            return new Column(tableName, column);
        }
    }
    return null;
}
 

private Column getColumnByExpr(SQLPropertyExpr expr) {
    SQLExpr owner = expr.getOwner();
    String column = expr.getName();
    boolean containSchema = false;
    if (owner instanceof SQLIdentifierExpr || owner instanceof SQLPropertyExpr) {
        String tableName;
        if (owner instanceof SQLPropertyExpr) {
            tableName = ((SQLPropertyExpr) owner).getName();
            if (((SQLPropertyExpr) owner).getOwner() instanceof SQLIdentifierExpr) {
                containSchema = true;
                tableName = ((SQLIdentifierExpr) ((SQLPropertyExpr) owner).getOwner()).getName() + "." + tableName;
            }
        } else {
            tableName = ((SQLIdentifierExpr) owner).getName();
        }
        checkAliasInColumn(tableName, containSchema);
        return new Column(tableName, column);
    }

    return null;
}
 

/**
 * Equal or not equal to relationship transfer
 * E.g.  ntest.id = mtest.id and xtest.id = ntest.id
 * we try to add a derivative relationship "xtest.id = mtest.id"
 * so when there has limit in mtest.id the xtest.id can also get the limit
 * P.S.:Only order insensitive operator can be optimize,like = or <=>
 *
 */
private void relationMerge(Set<Relationship> relationships) {
    HashSet<Relationship> loopReSet = new HashSet<>();
    loopReSet.addAll(relationships);
    for (Relationship re : loopReSet) {
        for (Relationship inv : loopReSet) {
            if (inv.getOperator().equals(re.getOperator()) && (inv.getOperator().equals("=") || inv.getOperator().equals("<=>"))) {
                List<Column> tempSet = new ArrayList<>();
                addAndCheckDuplicate(tempSet, re.getLeft());
                addAndCheckDuplicate(tempSet, re.getRight());
                addAndCheckDuplicate(tempSet, inv.getLeft());
                addAndCheckDuplicate(tempSet, inv.getRight());
                if (tempSet.size() == 2) {
                    Relationship rs1 = new Relationship(tempSet.get(0), tempSet.get(1), inv.getOperator());
                    Relationship rs2 = new Relationship(tempSet.get(1), tempSet.get(0), inv.getOperator());
                    if (!relationships.contains(rs1) && !relationships.contains(rs2)) {
                        relationships.add(rs1);
                    }
                }
            }
        }
    }
}
 

@Override
protected void handleCondition(SQLExpr expr, String operator, SQLExpr... valueExprs) {
    if (expr instanceof SQLCastExpr) {
        expr = ((SQLCastExpr) expr).getExpr();
    }

    Column column = this.getColumn(expr);
    if (column != null) {
        Condition condition = new Condition(column, operator);
        this.conditions.add(condition);

        SQLExpr[] var12 = valueExprs;
        int var13 = valueExprs.length;

        for (int var8 = 0; var8 < var13; ++var8) {
            SQLExpr item = var12[var8];
            Column valueColumn = this.getColumn(item);
            if (valueColumn == null) {
                if (item instanceof SQLNullExpr) {
                    condition.getValues().add(item);
                } else {
                    Object value = SQLEvalVisitorUtils.eval(this.getDbType(), item, this.getParameters(), false);
                    condition.getValues().add(value);
                }
            }
        }

    }
}
 

private Column getColumnByExpr(SQLIdentifierExpr expr) {
    String column = expr.getName();
    String table = currentTable;
    if (table != null) {
        return new Column(table, column);
    }

    return null;
}
 

/**
 * get table name of field in between expr
 *
 */
private String getOwnerTableName(SQLBetweenExpr betweenExpr, String column) {
    if (aliasMap.size() == 1) { //only has 1 table
        return aliasMap.keySet().iterator().next();
    } else if (aliasMap.size() == 0) { //no table
        return "";
    } else { // multi tables
        for (Column col : columns.values()) {
            if (col.getName().equals(column)) {
                return col.getTable();
            }
        }

        //parser from parent
        SQLObject parent = betweenExpr.getParent();
        if (parent instanceof SQLBinaryOpExpr) {
            parent = parent.getParent();
        }

        if (parent instanceof MySqlSelectQueryBlock) {
            MySqlSelectQueryBlock select = (MySqlSelectQueryBlock) parent;
            if (select.getFrom() instanceof SQLJoinTableSource) {
                SQLJoinTableSource joinTableSource = (SQLJoinTableSource) select.getFrom();
                //FIXME :left as driven table
                return joinTableSource.getLeft().toString();
            } else if (select.getFrom() instanceof SQLExprTableSource) {
                return select.getFrom().toString();
            }
        } else if (parent instanceof SQLUpdateStatement) {
            SQLUpdateStatement update = (SQLUpdateStatement) parent;
            return update.getTableName().getSimpleName();
        } else if (parent instanceof SQLDeleteStatement) {
            SQLDeleteStatement delete = (SQLDeleteStatement) parent;
            return delete.getTableName().getSimpleName();
        }
    }
    return "";
}
 

/**
     * 从between语句中获取字段所属的表名。
     * 对于容易出现ambiguous的（字段不知道到底属于哪个表），实际应用中必须使用别名来避免歧义
     * @param betweenExpr
     * @param column
     * @return
     */
    private String getOwnerTableName(SQLBetweenExpr betweenExpr,String column) {
        if(tableStats.size() == 1) {//只有一个表，直接返回这一个表名
            return tableStats.keySet().iterator().next().getName();
        } else if(tableStats.size() == 0) {//一个表都没有，返回空串
            return "";
        } else {//多个表名
            for (Column col : columns.keySet())
            {
                if(col.getName().equals(column)) {
                    return col.getTable();
                }
            }
//            for(Column col : columns) {//从columns中找表名
//                if(col.getName().equals(column)) {
//                    return col.getTable();
//                }
//            }

            //前面没找到表名的，自己从parent中解析

            SQLObject parent = betweenExpr.getParent();
            if(parent instanceof SQLBinaryOpExpr)
            {
                parent=parent.getParent();
            }

            if(parent instanceof MySqlSelectQueryBlock) {
                MySqlSelectQueryBlock select = (MySqlSelectQueryBlock) parent;
                if(select.getFrom() instanceof SQLJoinTableSource) {//多表连接
                    SQLJoinTableSource joinTableSource = (SQLJoinTableSource)select.getFrom();
                    return joinTableSource.getLeft().toString();//将left作为主表，此处有不严谨处，但也是实在没有办法，如果要准确，字段前带表名或者表的别名即可
                } else if(select.getFrom() instanceof SQLExprTableSource) {//单表
                    return select.getFrom().toString();
                }
            }
            else if(parent instanceof SQLUpdateStatement) {
                SQLUpdateStatement update = (SQLUpdateStatement) parent;
                return update.getTableName().getSimpleName();
            } else if(parent instanceof SQLDeleteStatement) {
                SQLDeleteStatement delete = (SQLDeleteStatement) parent;
                return delete.getTableName().getSimpleName();
            } else {
                
            }
        }
        return "";
    }
 

/**
 * find how mach non-repeating column in 2 relationships
 * E.g. A = B and B = C the result size is 2
 * A = B and C = D the result size is 4
 * A = B and B = A the result size is 0
 * when the result size is 2,we can know that there is 3 columns in  2 relationships
 * and the derivative relationship may be needed
 *
 */
private void addAndCheckDuplicate(List<Column> tempSet, Column tmp) {
    if (tempSet.contains(tmp)) {
        tempSet.remove(tmp);
    } else {
        tempSet.add(tmp);
    }
}