SQL Query Builder

SQL Query Builder

Overview

Based on DDC methodology (Chapter 2.1), this skill builds SQL queries for construction databases, supporting common construction data patterns like cost tracking, schedule management, and resource allocation.

Book Reference: "Типы данных в строительстве" / "Data Types in Construction"

Quick Start

from dataclasses import dataclass, field
from enum import Enum
from typing import List, Dict, Optional, Any, Union
from datetime import datetime, date

class QueryType(Enum):
    """Types of SQL queries"""
    SELECT = "select"
    INSERT = "insert"
    UPDATE = "update"
    DELETE = "delete"
    AGGREGATE = "aggregate"
    JOIN = "join"

class AggregateFunction(Enum):
    """SQL aggregate functions"""
    SUM = "SUM"
    AVG = "AVG"
    COUNT = "COUNT"
    MIN = "MIN"
    MAX = "MAX"
    GROUP_CONCAT = "GROUP_CONCAT"

class JoinType(Enum):
    """SQL join types"""
    INNER = "INNER JOIN"
    LEFT = "LEFT JOIN"
    RIGHT = "RIGHT JOIN"
    FULL = "FULL OUTER JOIN"

class ComparisonOperator(Enum):
    """Comparison operators"""
    EQ = "="
    NE = "<>"
    GT = ">"
    GE = ">="
    LT = "<"
    LE = "<="
    LIKE = "LIKE"
    IN = "IN"
    BETWEEN = "BETWEEN"
    IS_NULL = "IS NULL"
    IS_NOT_NULL = "IS NOT NULL"

@dataclass
class WhereCondition:
    """SQL WHERE condition"""
    column: str
    operator: ComparisonOperator
    value: Any
    table_alias: Optional[str] = None

    def to_sql(self) -> str:
        col = f"{self.table_alias}.{self.column}" if self.table_alias else self.column

        if self.operator == ComparisonOperator.IS_NULL:
            return f"{col} IS NULL"
        elif self.operator == ComparisonOperator.IS_NOT_NULL:
            return f"{col} IS NOT NULL"
        elif self.operator == ComparisonOperator.IN:
            values = ", ".join(f"'{v}'" if isinstance(v, str) else str(v) for v in self.value)
            return f"{col} IN ({values})"
        elif self.operator == ComparisonOperator.BETWEEN:
            return f"{col} BETWEEN {self._format_value(self.value[0])} AND {self._format_value(self.value[1])}"
        elif self.operator == ComparisonOperator.LIKE:
            return f"{col} LIKE '{self.value}'"
        else:
            return f"{col} {self.operator.value} {self._format_value(self.value)}"

    def _format_value(self, value: Any) -> str:
        if isinstance(value, str):
            return f"'{value}'"
        elif isinstance(value, (date, datetime)):
            return f"'{value.isoformat()}'"
        elif value is None:
            return "NULL"
        else:
            return str(value)

@dataclass
class JoinClause:
    """SQL JOIN clause"""
    table: str
    alias: str
    join_type: JoinType
    on_left: str
    on_right: str

    def to_sql(self) -> str:
        return f"{self.join_type.value} {self.table} {self.alias} ON {self.on_left} = {self.on_right}"

@dataclass
class SelectColumn:
    """Column selection with optional aggregate and alias"""
    column: str
    table_alias: Optional[str] = None
    aggregate: Optional[AggregateFunction] = None
    alias: Optional[str] = None

    def to_sql(self) -> str:
        col = f"{self.table_alias}.{self.column}" if self.table_alias else self.column

        if self.aggregate:
            col = f"{self.aggregate.value}({col})"

        if self.alias:
            col = f"{col} AS {self.alias}"

        return col

@dataclass
class OrderBy:
    """ORDER BY clause"""
    column: str
    descending: bool = False
    table_alias: Optional[str] = None

    def to_sql(self) -> str:
        col = f"{self.table_alias}.{self.column}" if self.table_alias else self.column
        direction = "DESC" if self.descending else "ASC"
        return f"{col} {direction}"


class ConstructionQueryBuilder:
    """
    Build SQL queries for construction databases.
    Based on DDC methodology Chapter 2.1.
    """

    def __init__(self, dialect: str = "postgresql"):
        self.dialect = dialect
        self.schemas = self._define_construction_schemas()

    def _define_construction_schemas(self) -> Dict[str, Dict]:
        """Define common construction database schemas"""
        return {
            "projects": {
                "columns": ["id", "name", "code", "status", "start_date", "end_date", "budget", "client_id"],
                "primary_key": "id"
            },
            "cost_items": {
                "columns": ["id", "project_id", "wbs_code", "description", "budgeted_cost", "actual_cost", "committed_cost"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id"}
            },
            "activities": {
                "columns": ["id", "project_id", "name", "wbs_code", "start_date", "end_date", "duration", "status", "percent_complete"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id"}
            },
            "resources": {
                "columns": ["id", "name", "type", "rate", "unit"],
                "primary_key": "id"
            },
            "resource_assignments": {
                "columns": ["id", "activity_id", "resource_id", "units", "cost"],
                "primary_key": "id",
                "foreign_keys": {"activity_id": "activities.id", "resource_id": "resources.id"}
            },
            "change_orders": {
                "columns": ["id", "project_id", "number", "description", "amount", "status", "submitted_date", "approved_date"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id"}
            },
            "invoices": {
                "columns": ["id", "project_id", "number", "amount", "status", "invoice_date", "due_date", "paid_date"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id"}
            },
            "materials": {
                "columns": ["id", "name", "category", "unit", "unit_cost"],
                "primary_key": "id"
            },
            "material_requisitions": {
                "columns": ["id", "project_id", "material_id", "quantity", "required_date", "status"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id", "material_id": "materials.id"}
            },
            "daily_reports": {
                "columns": ["id", "project_id", "report_date", "weather", "temperature", "crew_count", "notes"],
                "primary_key": "id",
                "foreign_keys": {"project_id": "projects.id"}
            }
        }

    def select(
        self,
        table: str,
        columns: List[Union[str, SelectColumn]],
        conditions: Optional[List[WhereCondition]] = None,
        order_by: Optional[List[OrderBy]] = None,
        limit: Optional[int] = None,
        offset: Optional[int] = None
    ) -> str:
        """Build a SELECT query"""
        # Format columns
        cols = []
        for col in columns:
            if isinstance(col, str):
                cols.append(col)
            else:
                cols.append(col.to_sql())

        query = f"SELECT {', '.join(cols)}\nFROM {table}"

        # WHERE clause
        if conditions:
            where_parts = [c.to_sql() for c in conditions]
            query += f"\nWHERE {' AND '.join(where_parts)}"

        # ORDER BY
        if order_by:
            order_parts = [o.to_sql() for o in order_by]
            query += f"\nORDER BY {', '.join(order_parts)}"

        # LIMIT/OFFSET
        if limit:
            query += f"\nLIMIT {limit}"
        if offset:
            query += f"\nOFFSET {offset}"

        return query + ";"

    def select_with_joins(
        self,
        main_table: str,
        main_alias: str,
        columns: List[SelectColumn],
        joins: List[JoinClause],
        conditions: Optional[List[WhereCondition]] = None,
        group_by: Optional[List[str]] = None,
        having: Optional[List[WhereCondition]] = None,
        order_by: Optional[List[OrderBy]] = None,
        limit: Optional[int] = None
    ) -> str:
        """Build a SELECT query with JOINs"""
        # Columns
        cols = [col.to_sql() for col in columns]
        query = f"SELECT {', '.join(cols)}\nFROM {main_table} {main_alias}"

        # JOINs
        for join in joins:
            query += f"\n{join.to_sql()}"

        # WHERE
        if conditions:
            where_parts = [c.to_sql() for c in conditions]
            query += f"\nWHERE {' AND '.join(where_parts)}"

        # GROUP BY
        if group_by:
            query += f"\nGROUP BY {', '.join(group_by)}"

        # HAVING
        if having:
            having_parts = [h.to_sql() for h in having]
            query += f"\nHAVING {' AND '.join(having_parts)}"

        # ORDER BY
        if order_by:
            order_parts = [o.to_sql() for o in order_by]
            query += f"\nORDER BY {', '.join(order_parts)}"

        # LIMIT
        if limit:
            query += f"\nLIMIT {limit}"

        return query + ";"

    def insert(
        self,
        table: str,
        data: Dict[str, Any]
    ) -> str:
        """Build an INSERT query"""
        columns = list(data.keys())
        values = []

        for v in data.values():
            if isinstance(v, str):
                values.append(f"'{v}'")
            elif isinstance(v, (date, datetime)):
                values.append(f"'{v.isoformat()}'")
            elif v is None:
                values.append("NULL")
            else:
                values.append(str(v))

        return f"INSERT INTO {table} ({', '.join(columns)})\nVALUES ({', '.join(values)});"

    def insert_many(
        self,
        table: str,
        columns: List[str],
        values: List[List[Any]]
    ) -> str:
        """Build a bulk INSERT query"""
        formatted_values = []

        for row in values:
            row_values = []
            for v in row:
                if isinstance(v, str):
                    row_values.append(f"'{v}'")
                elif isinstance(v, (date, datetime)):
                    row_values.append(f"'{v.isoformat()}'")
                elif v is None:
                    row_values.append("NULL")
                else:
                    row_values.append(str(v))
            formatted_values.append(f"({', '.join(row_values)})")

        return f"INSERT INTO {table} ({', '.join(columns)})\nVALUES\n{','.join(formatted_values)};"

    def update(
        self,
        table: str,
        data: Dict[str, Any],
        conditions: List[WhereCondition]
    ) -> str:
        """Build an UPDATE query"""
        set_parts = []

        for col, val in data.items():
            if isinstance(val, str):
                set_parts.append(f"{col} = '{val}'")
            elif isinstance(val, (date, datetime)):
                set_parts.append(f"{col} = '{val.isoformat()}'")
            elif val is None:
                set_parts.append(f"{col} = NULL")
            else:
                set_parts.append(f"{col} = {val}")

        where_parts = [c.to_sql() for c in conditions]

        return f"UPDATE {table}\nSET {', '.join(set_parts)}\nWHERE {' AND '.join(where_parts)};"

    def delete(
        self,
        table: str,
        conditions: List[WhereCondition]
    ) -> str:
        """Build a DELETE query"""
        where_parts = [c.to_sql() for c in conditions]
        return f"DELETE FROM {table}\nWHERE {' AND '.join(where_parts)};"

    # Construction-specific query templates
    def project_cost_summary(self, project_id: int) -> str:
        """Generate project cost summary query"""
        return self.select_with_joins(
            main_table="cost_items",
            main_alias="ci",
            columns=[
                SelectColumn("wbs_code", "ci"),
                SelectColumn("description", "ci"),
                SelectColumn("budgeted_cost", "ci", AggregateFunction.SUM, "total_budget"),
                SelectColumn("actual_cost", "ci", AggregateFunction.SUM, "total_actual"),
                SelectColumn("committed_cost", "ci", AggregateFunction.SUM, "total_committed")
            ],
            joins=[
                JoinClause("projects", "p", JoinType.INNER, "p.id", "ci.project_id")
            ],
            conditions=[
                WhereCondition("project_id", ComparisonOperator.EQ, project_id, "ci")
            ],
            group_by=["ci.wbs_code", "ci.description"],
            order_by=[OrderBy("wbs_code", table_alias="ci")]
        )

    def schedule_progress(self, project_id: int) -> str:
        """Generate schedule progress query"""
        return self.select_with_joins(
            main_table="activities",
            main_alias="a",
            columns=[
                SelectColumn("wbs_code", "a"),
                SelectColumn("name", "a"),
                SelectColumn("start_date", "a"),
                SelectColumn("end_date", "a"),
                SelectColumn("percent_complete", "a"),
                SelectColumn("status", "a")
            ],
            joins=[
                JoinClause("projects", "p", JoinType.INNER, "p.id", "a.project_id")
            ],
            conditions=[
                WhereCondition("project_id", ComparisonOperator.EQ, project_id, "a"),
                WhereCondition("status", ComparisonOperator.NE, "Completed", "a")
            ],
            order_by=[
                OrderBy("start_date", table_alias="a"),
                OrderBy("wbs_code", table_alias="a")
            ]
        )

    def resource_utilization(self, project_id: int) -> str:
        """Generate resource utilization query"""
        return self.select_with_joins(
            main_table="resource_assignments",
            main_alias="ra",
            columns=[
                SelectColumn("name", "r", alias="resource_name"),
                SelectColumn("type", "r", alias="resource_type"),
                SelectColumn("units", "ra", AggregateFunction.SUM, "total_units"),
                SelectColumn("cost", "ra", AggregateFunction.SUM, "total_cost")
            ],
            joins=[
                JoinClause("resources", "r", JoinType.INNER, "r.id", "ra.resource_id"),
                JoinClause("activities", "a", JoinType.INNER, "a.id", "ra.activity_id")
            ],
            conditions=[
                WhereCondition("project_id", ComparisonOperator.EQ, project_id, "a")
            ],
            group_by=["r.name", "r.type"],
            order_by=[OrderBy("total_cost", descending=True)]
        )

    def change_order_summary(self, project_id: int) -> str:
        """Generate change order summary query"""
        return self.select(
            table="change_orders",
            columns=[
                SelectColumn("status", aggregate=AggregateFunction.COUNT, alias="count"),
                SelectColumn("amount", aggregate=AggregateFunction.SUM, alias="total_amount")
            ],
            conditions=[
                WhereCondition("project_id", ComparisonOperator.EQ, project_id)
            ]
        ).replace("SELECT", "SELECT status,")  # Add group by

    def cash_flow_projection(self, project_id: int) -> str:
        """Generate cash flow projection query"""
        return f"""
SELECT
    DATE_TRUNC('month', invoice_date) AS month,
    SUM(CASE WHEN status = 'paid' THEN amount ELSE 0 END) AS received,
    SUM(CASE WHEN status = 'pending' THEN amount ELSE 0 END) AS pending,
    SUM(amount) AS total
FROM invoices
WHERE project_id = {project_id}
GROUP BY DATE_TRUNC('month', invoice_date)
ORDER BY month;
"""

    def material_requirements(self, project_id: int, from_date: date, to_date: date) -> str:
        """Generate material requirements query"""
        return self.select_with_joins(
            main_table="material_requisitions",
            main_alias="mr",
            columns=[
                SelectColumn("name", "m", alias="material_name"),
                SelectColumn("category", "m"),
                SelectColumn("quantity", "mr", AggregateFunction.SUM, "total_quantity"),
                SelectColumn("unit", "m"),
                SelectColumn("required_date", "mr", AggregateFunction.MIN, "earliest_need")
            ],
            joins=[
                JoinClause("materials", "m", JoinType.INNER, "m.id", "mr.material_id")
            ],
            conditions=[
                WhereCondition("project_id", ComparisonOperator.EQ, project_id, "mr"),
                WhereCondition("required_date", ComparisonOperator.BETWEEN, [from_date, to_date], "mr"),
                WhereCondition("status", ComparisonOperator.NE, "Cancelled", "mr")
            ],
            group_by=["m.name", "m.category", "m.unit"],
            order_by=[OrderBy("earliest_need")]
        )

    def daily_report_summary(self, project_id: int, month: str) -> str:
        """Generate daily report summary for a month"""
        return f"""
SELECT
    COUNT(*) AS total_reports,
    AVG(crew_count) AS avg_crew,
    COUNT(CASE WHEN weather = 'Rain' THEN 1 END) AS rain_days,
    COUNT(CASE WHEN weather = 'Clear' THEN 1 END) AS clear_days
FROM daily_reports
WHERE project_id = {project_id}
  AND TO_CHAR(report_date, 'YYYY-MM') = '{month}';
"""

    def generate_parameterized(
        self,
        query: str,
        params: Dict[str, Any]
    ) -> tuple:
        """Convert query to parameterized format"""
        param_list = []
        param_query = query

        for key, value in params.items():
            placeholder = f"${len(param_list) + 1}" if self.dialect == "postgresql" else "?"
            param_query = param_query.replace(f":{key}", placeholder)
            param_list.append(value)

        return param_query, param_list


class QueryOptimizer:
    """Optimize SQL queries for construction databases"""

    def suggest_indexes(self, queries: List[str]) -> List[str]:
        """Suggest indexes based on query patterns"""
        suggestions = []

        # Common construction query patterns
        patterns = {
            "project_id": "CREATE INDEX idx_{table}_project ON {table}(project_id);",
            "wbs_code": "CREATE INDEX idx_{table}_wbs ON {table}(wbs_code);",
            "status": "CREATE INDEX idx_{table}_status ON {table}(status);",
            "date": "CREATE INDEX idx_{table}_date ON {table}({date_col});"
        }

        for query in queries:
            query_lower = query.lower()

            # Detect table from FROM clause
            if "from " in query_lower:
                table = query_lower.split("from ")[1].split()[0]

                if "project_id" in query_lower:
                    suggestions.append(patterns["project_id"].format(table=table))
                if "wbs_code" in query_lower:
                    suggestions.append(patterns["wbs_code"].format(table=table))
                if "status" in query_lower:
                    suggestions.append(patterns["status"].format(table=table))

        return list(set(suggestions))

    def analyze_query(self, query: str) -> Dict:
        """Analyze query for optimization opportunities"""
        analysis = {
            "has_select_star": "*" in query and "SELECT *" in query.upper(),
            "has_indexes_hint": False,
            "join_count": query.upper().count("JOIN"),
            "subquery_count": query.upper().count("SELECT") - 1,
            "recommendations": []
        }

        if analysis["has_select_star"]:
            analysis["recommendations"].append(
                "Avoid SELECT * - specify only needed columns"
            )

        if analysis["join_count"] > 3:
            analysis["recommendations"].append(
                "Consider breaking down query with CTEs for readability"
            )

        if analysis["subquery_count"] > 0:
            analysis["recommendations"].append(
                "Consider replacing subqueries with JOINs where possible"
            )

        return analysis

Common Use Cases

Build Cost Summary Query

builder = ConstructionQueryBuilder()

# Get project cost summary
query = builder.project_cost_summary(project_id=123)
print(query)

Build Custom SELECT Query

query = builder.select(
    table="activities",
    columns=[
        SelectColumn("name"),
        SelectColumn("status"),
        SelectColumn("percent_complete")
    ],
    conditions=[
        WhereCondition("project_id", ComparisonOperator.EQ, 123),
        WhereCondition("status", ComparisonOperator.IN, ["In Progress", "Delayed"])
    ],
    order_by=[OrderBy("percent_complete", descending=True)],
    limit=10
)

Build JOIN Query

query = builder.select_with_joins(
    main_table="invoices",
    main_alias="i",
    columns=[
        SelectColumn("name", "p", alias="project_name"),
        SelectColumn("number", "i", alias="invoice_no"),
        SelectColumn("amount", "i")
    ],
    joins=[
        JoinClause("projects", "p", JoinType.INNER, "p.id", "i.project_id")
    ],
    conditions=[
        WhereCondition("status", ComparisonOperator.EQ, "pending", "i")
    ]
)

Insert and Update Data

# Insert new cost item
insert_query = builder.insert(
    table="cost_items",
    data={
        "project_id": 123,
        "wbs_code": "03.01.01",
        "description": "Concrete Foundation",
        "budgeted_cost": 50000,
        "actual_cost": 0
    }
)

# Update progress
update_query = builder.update(
    table="activities",
    data={"percent_complete": 75, "status": "In Progress"},
    conditions=[
        WhereCondition("id", ComparisonOperator.EQ, 456)
    ]
)

Quick Reference

Resources

• Book: "Data-Driven Construction" by Artem Boiko, Chapter 2.1
• Website: https://datadrivenconstruction.io

Next Steps

• Use data-type-classifier to identify data types
• Use etl-pipeline for data integration
• Use kpi-dashboard for visualization